Plenty of non-medical web results for 腑分けする. I don't think it's that rare.
腑分 has the same kanji as 腑分け so rK is not applicable.

@@ -9 +9 @@
-<ke_inf>&rK;</ke_inf>
+<ke_inf>&sK;</ke_inf>
@@ -28,2 +27,0 @@
-<xref type="see" seq="1199270">解剖・2</xref>
-<misc>&rare;</misc>
@@ -32 +30 @@
-<gloss>sorting out</gloss>
+<gloss>putting in order</gloss>

GG5, etc.
腑分け	6741
解剖	1008168

The JEs just xref to 解剖. They also use "analysis" for sense 2, so I'm moving it up.

@@ -29,0 +30 @@
+<gloss>analysis</gloss>
@@ -31,2 +32 @@
-<gloss>sorting out (e.g. feelings)</gloss>
-<gloss>analysis</gloss>
+<gloss>sorting out</gloss>

sankoku
１．「古風」解剖
２．複雑なものを分類・整理すること。「自分の感情を～する」

https://kotobank.jp/word/腑分-2080850
腑分
① 解剖のこと
② 転じて、詳細に分析すること。

#Nonmedical, Dissecting characteristics of ....
性格を解剖	174	100.0%
性格を腑分け	0	0.0%   (does exist, just not enough for ngrams)

Confirmation that the medical usage is dated.
https://ja.wikipedia.org/wiki/解剖
江戸時代には腑分け（ふわけ）とも称された。

Can google "感情の腑分け" and "感情を腑分け". Neither is common enough for ngrams. Use in the wild:
https://twitter.com/lastbreath0902/status/1607482666458419200
...
そう、まるで大人みたいに自分の感情を腑分けできたのなら、起こっていないすれ違い。
それは生の感情を分割できない
...


yourei book result.  google translates as "understand" (in context)
再現可能な手法で自然を腑分けし、  Using a reproducible method to understand nature,
https://www.aozora.gr.jp/cards/000055/files/56499_51225.html

another result on marxism 要素の基本的性格を腑分けし
マルクスの強調点は、現在の社会構造を構成する諸要素を分析するだけでなく、それらの要素の基本的性格を腑分けし、概念へともたらすことを通じて、...

https://cjjc.weblio.jp/content/腑分けする
to arrange by kinds or classes; to arrange in order
classify

add [dated] to [1], created [2] and marked [rare]. (not impossible to find, but not-at-all common, and probably fine to use the xref instead).

[2] is not in daijs but is in sankoku and others. splitting lets us mark [dated] properly. (sense [2] does not appear to be dated).

It appears that [2] here is probably the same as  解剖[2] in the xref for most/all practical purposes. Any collocation with 腑分け appears to be present with 解剖 as well. 解剖[2] could probably be improved to make it clear that it is not medical (especially with the inclusion of "postmortem" in the glosses, which maybe does not belong). 

Here's "problem", the only term I've found ngrams for this and the xref:
問題を解剖	137	69.5%
問題を腑分け	60	30.5%

Other things that can be direct object of 腑分け(found in yourei):
感情 feelings
性格 the nature of something (e.g. man)
自然 nature itself
善悪 good and evil
...miscellaneous complex factors leading to Japanese militarization

Here's a very recent example in asahi shinbun's book review section, found googling "性格を腑分けし". "dissect the characteristics of" might actually be the most straight-forward gloss here.
https://book.asahi.com/jinbun/article/14329301
このような大胆な分析が説得力を持つのは、双系社会と長老原理に基づく古代社会への深い理解だけでなく、「徹底した史料批判」によって、史料自体が帯びる政治的性格を腑分けし実態をすくい上げていく手腕によるのだろう。

@@ -5,0 +6,4 @@
+</k_ele>
+<k_ele>
+<keb>腑分</keb>
+<ke_inf>&rK;</ke_inf>
@@ -13,0 +18,2 @@
+<xref type="see" seq="1199270">解剖・1</xref>
+<misc>&dated;</misc>
@@ -15,0 +22,11 @@
+<gloss>postmortem examination</gloss>
+</sense>
+<sense>
+<pos>&n;</pos>
+<pos>&vs;</pos>
+<pos>&vt;</pos>
+<xref type="see" seq="1199270">解剖・2</xref>
+<misc>&rare;</misc>
+<gloss>dissection (e.g. of a problem)</gloss>
+<gloss>sorting out (e.g. feelings)</gloss>
+<gloss>analysis</gloss>

Meikyo vt and vi additions to n,vs entries
-*- via bulkupd.py -*-

@@ -12,0 +13 @@
+<pos>&vt;</pos>

Entry created