I think tipping on itch.io is a great feature which sets it apart from other platforms. However, as far as I can tell it only works when you are purchasing something. I have gotten a lot of things for super cheap in the current bundle and if I liked something, I would like to also provide a tip for the creator without having to pay full price or wait for a sale. I have checked the game page, profile and creator home page and I couldn't find an option on either.

Since it's easily more than a $1000 to re-buy everything I like, I think it would be nice if I could instead easily donate, say, $5 to the creator as support (on top of leaving a review/ follow or share it on other channels). I am also aware that you as a platform would likely retain some amount of the tip, so it might become an opt-in for creators. Maybe it can be something similar to ko-fi.com, but fully integrated in your platform.

Since this tip would be independent from a purchase, it could also mean that you can tip a creator without owning anything from them.

I agree. Some buyers might find a project, buy it on a whim or download free without tipping, realize it's amazing, better than they expected it to be after they download it and experience it, and want to tip *after* having experienced it. I can see this being useful both for myself as a creator, and as a player who has been pleasantly surprised by several of the games I've bought, only to realize the tipping option's no longer easy to do post-purchase.

-- Matthew Hornbostel, game dev, game player, and maker of game assets: https://matthornb.itch.io/