Yeah that'd work
I'm sure it would be possible to make something similar from an Antminer type machine too - one big waterblock per board, plumbed in to a common water system, then you can move the heat wherever you want it.
I'd like a couple of R4s to heat kitchen too, but they never come up for sale at sensible prices.
I've been wondering about watercooling the Vegas but they're doing ok in the airing cupboard
