I requested this a few months back and I know your priority right now is still to tune the animations and release v1.0, but the game can be more interesting and attractive if we allow 4 human players playing doubles together. I've tried third-party apps that allow keyboards to be shared, but they are never close to be perfect (input delay etc.). Sometimes when you are bored of singles, playing doubles can be refreshing, and playing alongside the AIs is just not as fun and realistic.
I doubt any other tennis game (at least the good ones) has that feature right now. So having that can be a huge plus when you have these new competitors for tennis simulators on the market. And without any doubt I'm not the only one interested in this feature. Just hoping you would still take that into consideration.
Have a great day!