This may be so, but I think, honestly, not..
All sorts of lathes by thousands have been used on ships and boats of all types for decades and worked fine.
As you said, if it has an accurate-to-lathe-body (spindle) subframe, this will be a great help, and You can just move it / chuck the subframe into any place and it will be fine.
No personal experience on that lathe.
But boats/yachts/ships twist, quite a lot, in machinist terms.
This does not hurt any lathe, but for top-accuracy the lathes should theoretically be soft-mounted on relatively rigid subframes.
Afaik, this is not routinely done.
A huge nr of manual lathes are on soft mounts and do excellent work.
The common wisdom and factory recommendation on manual lathes is soft mounts.
I am not advocating/insisting on soft mounts ...
just pointing out they are the common-average factory recommendation, and work well.
A hard mount is modern practice with big cnc turning centers (+vmcs), that are all soft and floppy, volumetrically.
Worth noting the 140 was designed to go on the back of a Army or Air Force 10 ton Truck or in the engineering shop of a ship, frigate or battle ship. So leveling is not essential but preferred.
That is why it is Near fatal to ever part the lathe from the special frame it is bolted to.
For that reason it is the only lathe I know that can be put on wheels and still stay accurate.
Mine is on wheels ! I posted a pics long ago