Stacking injection is literally the same thing as queueing units, except the command is issued via the Queen on the Hatchery, as opposed to the Hatchery onto itself. I’m actually fine if we want to remove unit queuing to increase skill cap, but I suspect that will hurt Terran the most.
Out of the 3 macro abilities (Chronoboost, Inject, Mules), Inject, even with queuing, is the most punishing and irrecoverable one, as long as you don’t cap Orbital and Nexus energy.
Mules: if you drop these late, assuming you forgot and not because you held onto the energy for scans, you would still gain the 240 (?) minerals over the course of the mule. You would be getting it late which would delay your build, but you would still get it
Inject: if you inject late, those are larva you will always be missing because consecutive injections do not allow you to catch up on what you have had before just at a later timing.
Chronoboost: if you Chronoboost late, as long as you didn’t cap Chrono energy doing so, you can still continuously pump it into a building of your choice. Your build will still be delayed you would still cut that X second off total production/research time, based on the number of Chronoboost you throw into the building.
In fact, if we want to remove Larva Inject, an appropriate action to do for both Protoss and Terran would be that you cannot Chronoboost more buildings than you have Nexus for, and you cannot have more Mules than you have Orbital Commands for. I personally wouldn’t have an issue against that, but it actually removes a lot of intentional banking potential.
If I forgot a Mule and banked to 100 energy, I can drop 2 mules at the same time and it would give the same amount of mineral at the end of these 2 mules compared to if I dropped one at 50 energy and another one at 50 energy.
If I forgot an inject, that is 3 (?) larva gone forever. I cannot get these 3 larva even if i queue 50 injects into it.
If I bank 100 energy in a Nexus and I wanted to chronoboost a specific building, the end result would be the same as long as I can get 2 full chronoboost on that research.
Don’t get me wrong, delayed timing is bad especially for a high level timing attack, but missing inject is far, far more punishing because it’s not just time lost; it’s also resource permanently lost.