I don't like the "formed directly in its own packaging" as it implies the processing takes place there, and it doesn't - it just sets there. But I really can't think of a succinct way of expressing that.

Thank you, yes, wordiness is an ongoing weakness. Though I'm becoming a mini-expert on all kinds of random topics...

Having researched and written so much, I really tried for a more concise [expl].  It's just not easy.

I've made a second suggestion of just cribbing the wikipedia note.  At least it "suggests" what's special about juten vs. other tofus. (traditionally formed in large blocks, cut into small blocks, and placed into containers with water added).

"tofu in sealed packaging" has somewhat the same issue as "packaged". All varieties of grocery-store tofu are sold in sealed packaging. It's just a question of when the sealing happens. The defining aspect of this tofu is that it is uncongealed/liquid when sealed into the container.

The gloss would be simpler if tofu was "cooked". ("tofu cooked in sealed packaging").  Unfortunately, this isn't considered cooking. I haven't found a concise, unambiguous English word that works. (set, set up, congealed, hardened, coagulated). 

"tofu coagulated in its own packaging" is correct, it just looks kind of offputting...  

"formed" seems as good as anything.

@@ -21 +21 @@
-<gloss g_type="expl">(silken) tofu in sealed packaging</gloss>
+<gloss g_type="expl">(silken) tofu formed directly in its own packaging</gloss>

https://delishkitchen.tv/articles/887#contents2
充填豆腐	2089

Nice (if over-wordy) analysis. I think this simpler gloss works.

@@ -9 +9 @@
-<ke_inf>&rK;</ke_inf>
+<ke_inf>&sK;</ke_inf>
@@ -21,2 +21 @@
-<gloss>juten tofu</gloss>
-<gloss g_type="expl">(silken) tofu heated and formed within its own sealed packaging</gloss>
+<gloss g_type="expl">(silken) tofu in sealed packaging</gloss>

A modest history of the development of this product:
Uses: Packaged lactone silken tofu (juten-dofu)...("filled tofu")
https://www.soyinfocenter.com/HSS/tofu7.php

"Soyfoods", winter 1982
https://www.google.co.jp/books/edition/Soyfoods_Winter_1982/UF1u8rg1jLcC?hl=en&gbpv=1&dq="juten+tofu"+"filled"&pg=PA22&printsec=frontcover
The Japan Packaged Tofu Association... handles the growing sector that produces "lactone silken tofu"(juten dofu), literally "filled tofu, heat coagulated, formed in the package"... juten has captured 10% of the market.

How it's made:
充填とうふができるまで
https://www.youtube.com/watch?v=NRQ4vFa46z4

The form without rendaku seems to be preferred by manufacturers (and ngrams).  Google 充填とうふ vs 充填どうふ. Some example of 充填とうふ:
http://machida-shokuhin.co.jp/lineup/zyuuten.html
https://www.kyotofu.co.jp/itemlist/item_cat/fill
https://www.i-love-tofu.jp/umayakko

One example of 充填豆腐 as sold in the west.  Morinaga was one of the original developers and exporters of the technology.  All exported Morinaga tofu is 充填豆腐.  It simply is not labeled in any remarkable way whatsoever. (except "long shelf life", which is particular to Morinaga and not required. Grocery 充填豆腐 is good for ~2 weeks).
https://morinaganutrition.com/products/mori-nu-silken-tofu-extra-firm

https://www.japanesefoodguide.com/types-of-tofu/
Jūten tōfu (Long shelf-life pasteurized tofu)
Jūten tōfu (充填豆腐, じゅうてん・どうふ) is pasteurized, and is heated then cooled in its packaging. It usually comes packaged in paper cartons or comes vacuum-packed, and has a longer shelf-life than regular packaged tofu.

https://www.likejapan.com.au/column/food-culture/tofu.html
Most of the tōfu sold in supermarkets is generally jūten-tōfu, also known as jūten-kinugoshi-tōfu. This type of tōfu is made by adding setting agents to cooled tōnyū and pouring it directly into a package before heating it to make it set

https://www.justonecookbook.com/tofu-the-nutrient-rich-superfood/
Jyuten (Juten) tofu is shelf-stable kinu tofu, packaged without water. It’s made by the soybeans and nigari mixture seal packed and cooled in the container to harden. 

Here's an example of an English translation of a Japanese product in the Japanese market:
https://eng.topvalu.net/items/detail/4549741779975/
Name	juten tofu (filled tofu)
Ingredients	soybean(Canada)

充填豆腐	2089	94.1%
充塡豆腐	0	0.0%
充填とうふ	132	5.9%
充塡とうふ	0	0.0%
充填どうふ	0	0.0%
充塡どうふ	0	0.0%

The *only* mention wikipedia English gives is an aside in the "coagulants" section:
https://en.wikipedia.org/wiki/Tofu
Glucono delta-lactone (GDL):... Using GDL as a coagulant, silken tofu can be formed directly in its container, as it does not require pressing

wikipedia.jp claims an English gloss of "packaged tofu", but this is a bit silly.  All tofu in the grocery store is "packaged".  Google "packaged tofu" yields nothing on this.

There is literally no adequate English gloss. In the west this product is called... "tofu". Or marketed as just-another "silken tofu".

"jūten tofu" yields the most useful search responses (both google and google book search).

I had added a [lit] gloss of "packed tofu" ("filled tofu" also possible).  But this is 1. literal/derivable, and 2. all-but-useless.

refs. suggest non-rendaku reading is the most accepted. じゅうてんとうふ

充塡豆腐 appears in reputable sources. (and 充塡 is just a less common alt. of 充填).

It seems to be called 充填 because the tofu completely fills its packaging. It's basically airtight, vs. traditional tofu cut from large blocks, with each block floating in water.

I bought a pack of 充填豆腐. Maybe 6 brands to choose from. Labeled on the front as silken tofu (絹ごし豆腐), "nutritional info/legal name" 名称 for all products states: 充填豆腐

If you want to be really crazy with glosses, the 1982 "Soyfoods Industry Directory & Databook" called this "packaged lactone silken tofu" (vs. bagged lactone silken tofu).  "lactone", or GDL(Glucono-delta-lactone), is the coagulant, but it isn't unique to this product either.

@@ -6,0 +7,7 @@
+<k_ele>
+<keb>充塡豆腐</keb>
+<ke_inf>&rK;</ke_inf>
+</k_ele>
+<r_ele>
+<reb>じゅうてんとうふ</reb>
+</r_ele>
@@ -13 +20,3 @@
-<gloss>packaged tofu</gloss>
+<gloss>jūten tofu</gloss>
+<gloss>juten tofu</gloss>
+<gloss g_type="expl">(silken) tofu heated and formed within its own sealed packaging</gloss>

Wiki: 今日、豆腐は木綿豆腐、ソフト豆腐、絹ごし豆腐、充填豆腐の4種に大別される

Not the usual meaning of 充填. WWW images seem mostly to be of pre-packaged tofu. I suspect Eijiro's "filled tofu" is a bit off.

@@ -14 +13,0 @@
-<gloss>filled tofu</gloss>