I know it’s not exactly what you are asking, but on kagi.com you can increase & decrease weighting of any domain in search results. You can also create custom url redirects, which could work for cases where the url contains the same information but on another domain (i.e. redirect youtube result to same video ID on piped).
But I’m not sure if kagi fits your needs, while it is privacy focused it is a commercial product and it asks a monthly subscription fee
Alternatively when creating the ventoy installation you can chose to leave X amount of space behind the ventoy partition and then create your own data partition there afterwards. You lose the advantage of “dynamically” sharing the available space between ventoy and your data, but with the seperqte partition you can use whatever filesystem you like for your data, and there is a clear seperation between ventoy and your other data.