That is insanely awesome information to know. I knew someone who made a rear set of Corolla coil overs utilizing split collars and everyone thought it was sketchy, including me. 6,000lbs is insane weight bearing for a split collar would've never thought that was possible even me with my poor welding skills could lay some MIG tacks down and make sure it NEVER moves. For years I always did the weld on collar method and paid someone due to my welds SUCK, and I can't afford a welder unit.
I'll be doing this once I sell my 510 BMC/acquire funds, I have a bunch of spare coil over parts laying around including adjustable inserts, metal slim profile top hats, etc so hopefully they will fit the OE casings (assuming they're 45mm OD) and eliminate the need for a bunch of cutting/welding swapping knuckles to stub mounts or spending hundreds fitting Y33 arms, brakes and custom drilled 4 lug hubs.
Sorry OP if thread jacking.