I think I am looking around for a "small" independent 4 jaw.
Some time back I saw Steffen Gottswinter (spelling) make a video where he used offset drilled bushings to grind off center tool shanks. This is handy for making things like boring bars threading tools, and inside grooving tools. You can even make a single form single flute thread mill this way in a pinch. Basically an inside threading tool.
I certainly could do this and its pretty easy. I just need to decide what sizes I want to make first, and how far they should be offset. For any particular tool I think they would strongest if the offset is only enough to make that particular tool. I have made tool and drill bushings before. Solid and split both. I have run my solid bushings at upto 34,000 rpm (some of them, and I've got a split bushing for a drill that I use at 5,000 all the time. I'm confident in my ability to make them. The thing is for this purpose I might have to make dozens of them eventually.
This morning I was watching Steve Summers video on setting up a 4 jaw to use on his tool and cutter grinder to grind offset clearance diameters like Steffen's bushings, but you just dial it in on the 4 jaw. When your offset is ground switch it to a collet to grind in the tool's cutting surfaces/edges.
Steve used a much larger chuck than I would have chosen. I don't think I could fit that on my little single lip tool and cutter grinder (d-bit grinder). I think a little 2 inch or maybe 3 inch that would open to hold upto a piece of half inch carbide or HSS would be perfect for me. They make scroll chucks that small. I have a couple (I use them like centers on rotating arbors), but they are scroll chucks. I have not seen an independent jaw that small.
Quality doesn't even have to be all that great. It's just for grinding a clearance offset to allow for maximum remaining material for strength. The important griding all comes after its swapped back to a collet.