I'm not familiar with the series, but based on what you've described, I think the way I would handle it is to have a category on each game for its "HD" and "To Go" versions. I think that would be a lot clearer than lumping all of the mobile versions under one leaderboard.

Dunno if they'll see this thread, they're pretty busy people.

However, there is large precedent for subcategories for different versions, many games use the system. No one will complain if you go ahead.

Define “okay”. If your idea works for your LBs and it doesn’t make anything confusing or hard to submit correctly, then it’s probably fine. Run it by the community if you have even a small one for their opinion.

There is no right way to set up an LB, it all depends on what makes sense for the game.

You can try combining versions of games in cases where they make sense. Whatever you think makes the most sense is probably fine enough, so long as it isn't ridiculous in comparison to the rest of the games on the site.