As no-one is broadcasting or streaming or supplying discs in 4:4:4 DV @60Hz, the only folk who that is likely to affect is going to be gamers; and if you're gaming and able to concentrate enough to spot the difference between 4:4:4 and 4:2:2/4:2:0 at normal seating distances for 4K then I think you're probably not doing it right...! I don't believe there is any source that refuses to do DV at 60Hz because it can't get a 4:4:4 link?
I think HDBT is a good solution for many applications, but it is always trailing the capabilities of direct HDMI solutions. If you want to be right at that bleeding edge then don't go HDBT. For what it is worth I don't think it has much of a future as single links past 18G (they've not even got there fully yet).
Back to the OP; they don't have a conduit and seem to want to avoid the building works and / or exposed cables; if they can get the Wyrestorm solution for £100 from a trusted source, and it supports the formats they need, I'd have just bought it already as at that price I'm sure it could be punted onwards for no loss; it's almost not worth the thought energy. I paid more for my Atlona at trade cost, and I'm happy at that. If it works and does the job for them, great, if not, move it on and time to get busy with the tools. Job done.
You're right, I should have just grabbed it. But I dithered and its gone out of stock now :/ As you say I could have just sold it if it didn't suit my needs
Will keep an eye out for another one. Or get my tools out and run that new cable