I've been kneeling for a few months. It's not one of my favorite activities because, yes, it feels weird. It's better on, say, a bed, which is where I do most of my kneeling. In fact, kneeling feels normal on a bed. And I use a foam pad when on the ground and that's not too bad. (Just feels weird.) I don't like kneeling on carpets (thinner padding), but can, and do with the grandchildren. Harder floors are just... no, thank you. But I can, if there's a really good reason.
You could try knee pads. I used these once on the floor and they felt a little weird (but they felt weird even on my original knees). I would do them again. They are something you could easily pack and have with you. Just a thought.
I think kneeling is something you can get used to doing. My OS told me my implants were good to go for kneeling but I probably wouldn't like it. He was right. But I like what kneeling can do for me, so... I've gotten quite okay with kneeling on the bed and things like sofas. And I get down to kneeling on a carpeted floor without more than a "I hope this doesn't last too long" thought. I kneel in church (not in joy but because). It's something I know I can do.
If you're motivated to kneel, and you know you should be able to do it with your implant, you will find ways to do it. If you do it a lot, I bet you even get used to it.