I don't think the literal gloss adds much because it's too similar to "neither this nor that". "No matter what" could be confusing.
Let's just leave it as it was for now. Not an easy one to translate.

@@ -13,2 +12,0 @@
-<gloss>no matter what</gloss>
-<gloss g_type="lit">it's not like this; it's not like that either</gloss>

Maybe this will do?

@@ -12,0 +13,2 @@
+<gloss>no matter what</gloss>
+<gloss g_type="lit">it's not like this; it's not like that either</gloss>

A very literal "it's not like this; it's not like that either", maybe? I don't know. I do think the entry is OK as it is.

"彼は我々のすることをああでもないこうでもないとけちをつけたがる  He's forever finding fault with what we do"
"彼は同僚がミスをするとああでもないこうでもないとうるさく言う癖があるみたいだ  He seems to have a habit of getting on his coworker's back when he makes a mistake"

It would be good to have glosses that cover the above usage but I'm struggling to think of any. It's not just about indecisiveness.

I don't think it's adv-to.