Giving a timer penalty to your automatic morph for building defenses is a very arbitrary rule. If defenses are problematic and make the game too static, then defenses should be nerfed or changed. Unintuitive rules to band-aid the problem are not a long-term solution.
Rules like that tend to be quite exploitable as well.
You could, for example, just keep your com back at home and it would morph faster than the other com pushing the front line, but occasionally plopping a turret or two to help with the push. You'd be rewarding passive play instead of aggressive, even when that aggression comes with turrets.
Or you could bring racketeers and constructors with your commander, use your com only to get mex and disarmed turret kills while your constructors plop defenses all around it (which can be hold fired when necessary to avoid getting last hits on mexes and turrets). Basically, your rules would bring last hitting from mobas into ZK where you have to make sure to get kills with the right units for optimal play. This would be the kind of tedious micromanagent that Zero-K tends to avoid.
There's also the problem that inexperienced players would probably be raged at quite a lot for not knowing or not exploiting all those rules.
I do agree that ZK could use to be more dynamic and less porcy. While unit balance seems to be in a decent spot with with very few exceptions (hi Swift), turret balance seems to have been ignored for the most part.