I think that you should get to lvl 30 by play time/xp alone.
When you get there you should be able to get another 5 dynamic levels split into MMR ranges.
lvl 30 is any player up to 1500 with sufficient time played
lvl 31 is 1500-1700
lvl 32 is 1700-1900
lvl 33 is 1900-2100
lvl 34 is 2100-2300
lvl 35 is 2300+
Yes, these last 5 levels would be dynamic so you can creep into lvl 33 for example the day you get over 1900 only to go back to 32 for not maintaining it.
if you are 2300+ MMR by the time you get to lvl 30 (eg smurfs) then it should also require additional xp to unlock those levels so you don't insta-level to 35.
Experienced players then have a reason to strive for keeping those last few levels, and cant make a lvl 35 and donate it to someone and have it stay 35 without any effort. It might need some sort of tutorial that when you unlock lvl 31 that it explains it is dynamic, but then newer pilots might still ignore that.
Would you guys be ok with potentially topping out at 32-33 if you are a fairly good player but not elite competition grade?
I'd be happy with lvl 32-33 and would be interested to see players above me and see it as a challenge.
Cheers,
6ixxer