[MathYouF]

> But now that the learning curve is flattening, I feel the weight of not having enough creative freedom to write something up quickly or try different designs

This sounds like the real problem, more than anything.

Perhaps it's a sign that the code reviews have done their job, and you've been trained well enough to become a code reviewer yourself.

It might benefit you to start asking for more authority to be discussing these new design ideas with whoever is in charge, and see what they have to say.

If you really think you know well enough to architect things on your own or improve architectural decisions, you should assert that belief and ask for opportunities to test it.