It should be noted that DVT by itself doesn’t really solve the problem here, only if DKG was involved for key creation and a full key was never reconstituted somewhere, which is why for Simple DVT a requirement for all integrations was that validator keys were created using DKG ceremonies where all cluster participants were participating was a requirement.
A similar approach in terms of “sharding” the key can be employed using Attestant’s Dirk, which Numic also identifies above as a a possible solution, and doesn’t require DVT.