Is it possible in the future to play live (test) the mods just how we can live play with the maps?

LiveView is heavily trimmed down specifically to allow quick, in-browser previews of maps. It isn't designed to act as a full client replacement, and native performance on a local PC will always be far superior.

Supporting mods in LiveView would technically be doable for a small subset of releases, but stability would be a major hurdle, and many mods simply wouldn't function in a browser environment at all.

My main focus right now is on a few major backend updates for the site. Once those are complete, I'll take a proper look at how feasible limited mod previewing might be.