I don't have an ML10, but have used a variety of linked belts on a variety of different machines.
I believe Boxford recommended and supplied one of the original linked belts designs, The Brammer, held together with a set of metal rivets.
When I bought my Super 7, it was also fitted with one of these, which worked fine, but was getting quite old; when new, the lathe would have been fitted with a standard V belt.
Since the belt was old enough to start to perish, I replaced it with one of the white plastic linked belts from RDG, though they are also supplied by other outlets.
It slipped for much of the time, even when thoroughly degreased.
I replaced it with their slightly more expensive black variant, which was no better.
I may have got the colours the wrong way round, but it doesn't matter, as they no longer list either.
They were made up of links of solid plastic and didn't appear to gave ant fabric reinforcing.
RDG now seem to supply Megadyne link belt, in green; this is still a form of plastic, but with an internal reinforcement.
Prior to RDG selling it, I'd already bought some from an eBay supplier for about £14.50 per metre.
It works fine on the Super 7, though I think you need more tension than a conventional V belt.
It's similar to the Fenner Powertwist, but cheaper; I've never used the Fenner belt so can't comment on it, though it seems highly regarded.
I then bought a Warco 720 Super 7 clone, which needed a new belt.
I still had the old Brammer, so used that initially, whilst awaiting a replacement.
I also had some new Nutlink in stock; I tried this, but it's physically deeper, so I couldn't select the lowest belt speed, as the metal joining bits fouled on the casting.
The same proved true of some T nut belt I had in stock.
I use both T Nut & Nutlink successfully on a pillar drill and power hacksaw, but there is more space around the pullies, and a greater distance between them.
I wouldn't use either on a small lathe, due to bulk and stiffness.
I also tried some smaller section T Nut on the motor drive for the Super 7. There's no obvious reason to, as a conventional V belt fits without and dismantling, but I had it in stock; It didn't work out, due to the greater depth fouling on the belt cover.
The Megadyne works fine, provided you get the tension correct; I used the guide from Fenner's site for their Powertwist.
I've also noticed, that if you have a worn pulley, such that a belt sits lower in the groove, both T Nut and Nutlink have their inner metal fasteners fouling the bottom of the groove.
A new conventional V belt, Megadyne, and I presume Fenner Powertwist, are OK
Bill