The bug report system (
https://boardgamearena.com/bugs?game=1354) is really the best place. It sends me an email whenever someone creates a new report or posts a reply, it keeps everything in one place for me, and it lets me assign a status to each report to mark it as under review, confirmed, fixed, etc. This lets me prioritize the work -- most developers are working as volunteers, so we have limited time for these games. I use the number of votes on a bug to help prioritize which things to focus on first.
While I do eventually read through all of the "ratings" (those things you're
sometimes prompted to enter at the end of the game), these are much less useful for both players and developers. For players, you have no way to go back and review what you wrote. For developers, there is no page that lets me reply to the comments or track them with statuses (in progress, confirmed, fixed, etc.). Also, unlike bug reports, I don't get emails or notifications about new "ratings", so I only check this once in a while when I remember to go look it up manually.
Anyway, I've edited the "How to play" page at
https://en.doc.boardgamearena.com/Gamehelphardback to add basic explanations for how double, trash, jail, uncover abilities work. I don't think this information really belongs in the game itself as a tooltip, for example, but putting it in the "How to play" section makes it available by just scrolling down below the game. Note that anyone can edit these "how to play" pages for any game, not just the developer, so feel free to make corrections or add something that you think would be useful to other players. The "How to play" is visible both within the game itself (underneath the play area in one of the tabs) and also before you start a game (one of the "Show more" buttons on the game detail page).