More advice for a book I’m writing : meteorology

Hello meteorologists. A few years ago, I was after some advice for a world I’ve created for my book. The answers were super helpful, and I changed a bunch of things. Here’s what I asked:

https://www.reddit.com/r/meteorology/comments/a07uju/advice_for_a_novel_im_writing/

I come again seeking your knowledge. I’ve added a super helpful picture this time: https://imgur.com/a/FD8hBOi

The basics are: the island is roughly 500km by 300km. The cliff things is 5km straight up, and there’s a pass of sorts cut into it.

Based on this geography, is it possible that there could be thermals rising along the face of the cliff? Could a bird – or light aircraft etc, use rising air currents to climb to about 5km up?

Thanks a lot for your insights.