01-02 Minor feature but still needs a little bit of coding to call this again and flag it so it doesn't retrigger itself.
05-06 Requires Larian to model Modrons. If they aren't in the game that's already approaching the amount of work needed to add a new race.
11-12 Requires Larian to code in the ability to change height. Could just grow or shrink the model but still that might cause bugs and would require some special coding.
15-16 Requires coding a new spell. Not hard at all, very simple but it's a similar amount of work to an average sub-class feature.
17-18 Pink beard made of feathers. Even if you just go with a pink beard you need to code in the ability for it to grow spontaneously. Do all models have beards? If not again more coding, more modelling.
And so on. It's death by a thousand cuts. Divine Soul requires like 2 new abilities, 3 if you can get to 14th level. Pyromancy is the same only the abilities are even easier to add in. I'm not predicting Wild Magic isn't making it in nor saying it shouldn't just that it's quite a lot tougher than a lot of competing sub-classes.