I let my culls free range until I can decide what to do with them. Bantams & standards. I've had some very interesting chicks happen that way. One thing about hybrid poultry is vigor is usually better. Almost all of my layers are hybrids, and they give me the best & largest eggs I have found anywhere.
These are all examples of hybrids from my yard birds:
A cockerel that is Australorp X RIR/JBG
Another that is Australorp X RIR/JBG/Australorp
This one is a white silkie X quail d'Anver
This pullet is from the above roo & and one of the hybrid laying hens
This is a little roo, he's an Araucana cross with ??? mystery hen?
And the funkiest roo of all, this guy. He's from a Red Pyle Modern bantam cock out of a Dutch Citron Silkie hen
Nothing too exotic but as you can see, a wide array of possibilities. For yourself, if it's what you enjoy, go for it. Just know that most roos will end up as meat birds and the outlet for them is very limited. The advice for Frizzled X Frizzled & Tufted X Tufted was spot on, keep that in mind.