My humble remarks....
1. Loading stainless reels make me want to rip my hair out and curse and nuns, therefore I only use Paterson plastic reels.
2. I use regular Scotch tape to attach film to the spool when I bulk load, and the Scotch tape survives processing nicely, I should think it could attach two 120 lengths on a single reel.
3. I have never used inversion agitation in 25 years of darkroom work. I just use the twister on the Paterson tanks (30 seconds initially, and 5 seconds every 30 seconds thereafter). BTW, my Paterson tanks are 20+ years old and still work fine, with no sticking ratchet-bearings.
4. Pro-tip: Use your scissors to cut a 1/16" chamfer on the sides of the leading edge, so the film doesn't bind as it is loaded onto the Paterson reel.
YMMV ;-)
- Danner