I paused leveling mine at 27 (last November).
Since then I used all my rex DNa to create and level Tryko and Erlidom (now 26 and 25).
During that time, I felt like it did it’s job pretty well. It gave out enough damage and withstood a reasonable amount of hits to keep me competitive in the arena. I Never really felt like it was lacking … the only time level made a difference was when it was against another indoraptor. Most of those battles come down to RNG and who’s evasive worked and who’s failed. Leveling up really wouldn’t have changed anything.
I’m back to fusing it now though since I’m out of Anky and Erlik …and cuz of the daily Rex supply too .
I’d reccomend getting indo to a comfortable level you can keep it at and where it does its job well while pursuing another rex hybrid with ingredients you can readily find. Both tryko and Erlidom are great in battle … but I’ve yet to see an Anky despite driving by several parks.