This would be a good system because safe, effective passive healing is no longer a roundstart possibility. One could get Tier 1 chems, but for what? An incredibly slow heal rate that can't even bring you out of crit? Tier 1 is targeted on small, distributed amounts of damage that do not require surgery, cryo, etc. Since they are so bad they are safe, without side effects.
Tier 2 is effective for quick healing, but cannot be abused. It'll wreck your liver if used in excess or without care, and is should be used for getting someone back on their feet ASAP, but not to get them to an even 100 health.
Finally theres tier 3. Safe, reliable chems that can be used reliably in the field of battle.
Not pictured are niche chems. Ideally I want as much content removed as possible to remove the over saturation of chems, and make our chem system more bare bones. I'm talking removal of chems that specify application method.
However, theres a flaw with one thing: tier 3. All one needs to do is spend some time making these chems, and they instantly get their safe, passive, effective heals for murderboning or whatever. Thats where a suggestion from tralezab comes into play. Basically, the more you upgrade a chem dispenser, the better chems you unlock. The higher the upgrade, the higher tier you can make. Just normal high efficiency parts would allow for Tier 2 chems to be made, and then better parts after that allow for Tier 3 chems (tier one can be made roundstart). This means work and inter department cooperation is necessary to unlock these chems.
If an overhaul of chem dispensers is too much, we could just make tier 3 chems require lavaland ores and stuff, but thats bandaid and not as good.