This is not some horny-quest question but something that never really gets to be explicitly laid out in setting, but...

How compatible are the demi-humans, humans, and humanoids with one another? (leaving out awn/erhsheghlien as they sort of go beyond normality due to magic and fiat)

We get an explicit example of humans and elves occasionally mingling with viable offspring.

Do we have any examples beyond humanity and elves?

Dwarves, elves, halflings, and humans all seem to have meaningful contact with one another.

The Vos seem to have a lot of savagery in common with their humanoid neighbors - but they also seem to sometimes ally or trade with the monstrous. Further, with Kriesha's domain of monsters there could be some Interesting considerations.

More broadly in DnD humans tend to be able to get their groove on with most humanoid creatures to produce not only viable offspring but children who have children of their own.

The Realms, and frankly because Mr. Greenwood is still very accessible and willing to accommodate questions like this, also has lots of answers to that end. Like Dwarves 'breeding true' or halflings and elves just producing a shorter half-elf that is almost indistinguishable from human-elf pairings.

That's where I'll leave it to see what you guys have or maybe you know of some obscure lore that I have yet to stumble on.

Cheers!