Thanks for the review! If you can also please leave a rating, as it helps a lot!
For extra poses for sprites, that's unfortunately dependant on funding as the artists of the team don't work for free. Also, the sprite artist is one person so that would increase his workload even further.
And Sonic Battle fighting is not possible to have in the Ren'py engine. Also, again, it would need a lot more art assets. Since fighting is not the focus of this game, that would be very much not worth it.