STP Root Bridge and VLT

Correct if I'm wrong, but I'm pretty sure that I read in the documentation somewhere that a VLT domain should be elected as the root bridge of your network. I am wondering why that is. What are the negative effects, if any, of not electing a VLT instance (if there is only one) as the root bridge of your network?

I suppose another question I have is if you have multiple VLT domains in a network, should they have higher priority than all non-VLT switches in your network? That is, should they be preferred for root bridge election for STP over all other switches in the network?

Edit: After a bit of research that I should have done before even posting this question, I think I have come to an understanding. Basically, any switch that is more likely to act as the "core" of the network should be the root bridge.

Typically, in a leaf-spine topology your VLT switches are likely to be used at the core or spine. This provides a redundant central trunk for the network. If a VLT domain is not the root bridge of a particular segment, one part of it may become isolated (blocked) due to a misconfiguration on another switch. Additionally, if the root bridge is not the switch that is most central to the network/segment, then the network will not be as efficient as it could be.