TCX and TUI haven't got sucked into the short turnaround high utilisation game that the Loco's have- they still operate as they have for years and 1-1.5 hour turnarounds are the norm.
But as you say yourself, they can only ever really operate two return trips per day because their average sector lengths are longer than that of say EZY or FR.
As such, there's no benefit in short turns for MT or TOM as on the whole it would never be sufficient enough to provide a third rotation. It's partially the same reason why low-cost long-haul has always been a challenge.
Good to see anyway MT are finally at LTN in some reasonable quantity. Just a shame it's only following such sad circumstances.