So after around 300 hrs of autochess and stream forum observations and learning, a few things have stuck out that I think may help this game even more (btw I think its the best version out there atm).
For starters there are 2 things you never hear someone say when talking about autochess which I think is a good place to start.
I wish there was MORE rng.
I wish the games were longer.
The 3rd thing I've observed in this community is you generally find is people love putting combinations together and enjoying the upgrade ride the most out of any aspect of this game/journey.
Now how can you make more of 3. and less of 1-2?
For starters, I think 1. and 3. are tied together. If you make it less rng, people will have more fun with the combination upgrades, but not to much that the thrill of chance isn't also in play as well (people seem to really like this even though I don't).
One idea I have for 1. and 3. and it actually works with 2. as well, is you increase the champion selection from 5-6. This is a 20% increase in consistent combination forming AND more fun for everyone getting closer to their goals/ideas just putting shit together. One side meta expanding benefit of this as well is it may allow for more reason to roll and upgrade sooner, since you have a better chance of getting what you need sooner, and veer away from the all to common (and general best strategy) of mainly saving and rolling later. If a game has a general best way to win, then it will limit skill cap, which I'd imagine you'd want to avoid if your making this a ranked feature.
The last thing I will add is, streamlining item accumulation so its more apart of the game and less hit or miss random. Dota Underworlds did a great job in making items certain each creep round. I'd say do something similar, but drop more items, allowing for more combinations, a build possibilities and strategy.