OK, thanks, I understand now.
Yeah, WPML has a lot of undesirable aspects. Polylang works OK for me, or for simple multilanguage sites, you can craft your own with a little custom code, but probably don’t want to go down that path.
If the site is expected to be large amount of content or it’s for a client, I’d recommend reconsidering Polylang, as once there’s a lot of content or other users need to manage the different translations, it will become very tedious.
But, I appreciate you wanting to keep the WP’s separate and we should be able to get that supported by plugin again in future.
I still think I can show some methods for you to proxy requests in meantime. Maybe not all within BunnyCDN, but I’ll try. I use CloudFront in AWS to do like this before for a client and worked fine, it looks like Bunny has enough functionality to also support, but I’ll need to test, maybe good time is when I test/fix the new Windows support for Bunny, then can create a few sites and test.