I don’t know if this has been mentioned elsewhere, and it is super simple, but it bears repeating.
If you have something that is available in a kit, but not available to be ordered by itself, that should be fixed.
Most notably is the V5 claw (and the small metal gear that comes with it). My district purchased 30 v5 upgrade kits and 10 V5 clawbot kits, so now I only have 10 V5 claws for my 40 robots. I also don’t have enough U channel (that comes with the v5 clawbot kit) to follow the basic clawbot design in my intro to robotics class. Also with that many kits and as many kids as I have, sometimes the parts get lost (like the little 12 tooth metal gear) and there is no way to replace it currently.
I would like others to comment with any other Kit only parts that they want to see standalone, because I know there are more examples.