Honestly, there's a lot that could be done. It's a matter of willingness and time. Bort spends a huge amount of time on the Time Break game and he does a ton of updates on GLB2.
There could be graphics updates to GLB1, like bigger better dots with more color options.
There should be mid season Rookie player options, which seems like it would be easy to code. Like Day X gives Y SPs and Z TPs.
The rest are opinion questions, which could cure or kill the game, or at the very least open a huge can of worms which could become a huge time suck for Bort.
Personally I'd like to see another round of "Accelerated Player Development"
https://glb.warriorgeneral.com/game/forum_thread.pl?thread_id=4686077 but that could completely kill off the game if a majority the tiny user base decides they don't want to develop new build theory. To me, that's the best part of the game. Others prefer the cookie cutter, and want to spit out the same dots they always do.
I'd love it if every season used the season 2 XP progression. 50xp per day, 500xp per game. But that's a ton of work for Bort, because of all the interrelated sub systems like BTs and VXP.