Since I feel like my response isn’t best suited for a poll format, I’ll put it here…
For example, here’s part of the text of the grammar item about と as a conditional…
In the same way as the 格助詞 (case-marking particle) と means ‘and’, sometimes it is translated as ‘if’. In these cases, it is considered to be far stronger than ば, なら, or たら (which express hypothetical outcomes). This is because one of the primary uses of とis highlighting 結果 ‘a result’. In these cases, と is actually a 接続助詞, and shows one of three things.
As I read this, I feel confused about what a 格助詞 is, insofar as I would think all particles would mark case to a degree (in the same way that Russian uses noun declensions and English uses word order (except when it doesn’t)). I also can’t tell whether 接続助詞 are a subset of 格助詞; it’s difficult to tell from the context. The use of 結果 here rather than the English “result” feels superfluous.
If it were me, I’d code in a floating window so that if I mouse-over 格助詞, I see something like this…
格助詞
Case-marking particle
A particle, usually attached to a noun, that indicates the noun’s grammatical case.
Examples:
①田中さんが本を読みます。
②先生に相談します。
③格好へ行きます。
I’d do something like this for 接続助詞…
接続助詞
Conjunction particle
A particle that indicates that a predicate has a semantic connection to the main clause. It can attach to nouns, adjectives, or verbs.
Examples:
①朝起きて顔を洗います。
②テレビを見ながらごはんを食べました。
③学校で勉強をしたり運動をしたりします。
These are just translations of pages from TUFS, but I really like how they lay out their explanations: 格助詞; 接続助詞.
A lot of this is an issue of design principle. Bunpro’s explanations exist in a sort of limbo: they can’t mislead students, but they can’t go into enough detail to cover every exception, edge case, and nuance.
I don’t know how one would implement this in a practical way within Bunpro’s existing code structure, but from my own experience as a teacher, the ideal is to start with a shallow explanation, then introduce a more thorough explanation once the student hits the Seasoned or Expert level.
Maybe something like this?
Beginner explanation:
と: A conjunction particle (接続助詞) that means “if” or “when.”
[example sentences here]
Adept explanation:
In the same way as the 格助詞 case-marking particle) と means ‘and’, sometimes it is translated as ‘if’. In these cases, it is considered to be far stronger than ば, なら, or たら (which express hypothetical outcomes). This is because one of the primary uses of とis highlighting 結果 ‘a result’. In these cases, と is actually a 接続助詞, and shows one of three things.
仮定の順接 - A result that is assumed to be true, and obvious.
確定の順接 - A result that is known to be true.
仮定の逆接 - The opposite of a result that is assumed to be true.
Due to this, the (B) part of a phrase using とas ‘if’, will always occur when (A) happens, as it is considered to be the result of (A).
Then for the Seasoned explanation, I’d use the one that’s currently on the Bunpro page. In short, I’d add more details in proportion to mastery.