why don't they provide the best move analysis on the 64-square board with Brazilian rules?
That's actually a very good question, I thought about it myself, too, and I think I know the answer now.
I'm not entirely sure, my answer is purely a speculation, but as far as I know, the engine that they're using (Scan) just doesn't provide support for Brazilian draughts yet.
And there aren't too many draughts (or any at all) engines on the market, which have an open source licence, which allows Lidraughts team to embed them into their platform.
For Lidraughts to be able to embed an engine, it has to be either:
b) the owner of the engine has to give permission for the engine usage inside Lidraughts.
Moreover, given that unfortunately draughts are less popular than chess, most programmers concentrate on writing chess engines instead of draughts engines, so this feature might not be available any time soon (not sure about that, but it's like a year since the support for Brazilian draughts was introduced and still there's not analysis available) :(
Maybe one day, someone will create an open source engine and then I'm sure Lidraughts team will add it here, because they really care about this website, but at this time, they have no option of doing that.
I hope that my answer helped you and I wish you a wonderful rest of the day :)
Lidraughts AI is running on draughtsnet github.com/RoepStoep/draughtsnet draughtsnet uses scan and scan cannot play Russian or Brazilian.
Indeed, we simply don't have an engine (yet) that supports 64-square variants. Of course we would love to add engine analysis and with that the other engine options for all variants that we offer. Unfortunately for now, we can't give any timeframe when this can be expected.