Hmm... When I encounter arm resistance of that sort in kotegaeshi, I find it's much easier to just change the technique, perhaps to something like rokkyo (hijikime osae, wakigatame).
Sometimes the most logical solution is right in front of us - thanks.
Key is adaptation for sure.
edit to add:
...but I have no clue what any of the moves you mentioned are.
Everything we do in 6th/5th kyu is primarily Ai Hanmi/Gyaku Hami with some shomen uchi, Kata Tori, & Suwari waza added in the mix. (with the typical: Shionage, Iriminage, Uchikaiten Nage, Kotegaeshi, Kokyu-ho, Udemkima nage - and of course ikkyo, nikkyo, sankyo.)
It will be nice to expand my current knowledge base beyond where it currently is...
But step-by-step, hopefully I can get my foundations rooted in the above first.
It has been helpful to have this forum to come to in order to post questions.
(particularly in light of the fact Im learning Aikido in a foreign language Im not fluent in...)
Looked up Rokkyo - pretty cool.