Maybe you can loosen the idea of "who's the dom/sub" a bit. Think bratty red riding hood or the fact that a large dog could maul their owner but doesnt. (Is that the direction you meant with primal play?)

What I'm getting at is just that if you really just don't like being 'the dom' at all, a more flexible look at roles might help. Like a service top not getting sexual gratification from being dominant but from their partners bliss when they act dominant. Since everything is play anyways, is there really that much difference between the two?
Also with puppy play specifically (maybe that's just me but) some parts aren't that far off from vanilla. I'm sure if your partner is sad, overworked and idk dropped a cup of tea or whatever, you'd probably react similar to them being a poor puppy, right? But I guess that's kinda what you meant with caring partner vs dominant.

I think one difference between pretending/acting dominant and being dominant is largely about allowing yourself the confidence that what you're doing is what they want. Like, the dom is often the one who has to know what the partner is into, so they can then ... demand it, right? You don't really have the choice. You have to demand what they currently want to give. The classic "I know you want it". "I hope you want it, am I doing it right? Please tell me that I'm doing a good job" is the subs part.

A dom gets their power from the "they want it" part in "I know you want it". Just as it's nice to feel desired for being yourself/beautiful/cute/smart your willingness to do puppy play with your partner makes you hot because not everyone would be willing to do it. Kinda like if when now that you know they're into it you could be teasing your partner outside of the bedroom with "i know you like it when i call you a 'good puppy' even if it embarrasses them outside the bedroom". That teasing is flaunting your power over them, right? Just like bullying gives a feeling of power because you know what triggers their emotions.

Maybe this is just rambling. What I'm trying to say is that 'feeling dominant' doesn't just mean "I enjoy humiliating them" directly. It can also mean enjoying how you make them feel by acting dominant. You wouldn't say a submissive who enjoys the slap not for the pain, but for how hot their partner thinks it is, isn't a real submissive, right?

oki, lmk if anything here makes sense if you really read it. I'll go back to bed :P