They wouldn't be rigid but I think the problem is more to what Neil alluded.
You need a drilling tailstock to make them usable. I looked at them a while back and if you put that into a regular MT2 tailstock you'd have to crank that wheel in each time. Trust me, you'd hate it quickly. Plus how are you going to set the depths each time? I'd have to look at it again but I don''t remember seeing stops on it (used to set your depth on each tool).
They are great on a Hardinge Small Ops lathe (also called a Handscrew machine, Speed Lathe, etc..). You setup all your tools in the turret and it advances to the next tool every time you bring the handle back all the way. The drilling depth is fairly deep, its been a long time but I am sure its at least 6 inches. It you were making up a bunch of threaded ferrules a small turret lathe would be the way to go. To use that MT2 turret gadget on one of these small cue lathes you'd have to makeup a drilling tailstock either like the Taig drilling tailstock or maybe one like the R&P type Neil was talking about. I honestly don't see that little turret gadget of much use unless you willing to do the R&D and machining to make up something that would work right.... even then, how often are you going to stand there and make up 100+ of anything? Making 20 pieces is not worth the time to setup let alone make up the tooling.... at least to me.
