Clearly I'm not a doctor: went to an ortho, got an MRI, and now I'm two days post-op. The distal tendon was 90% torn. Got the button procedure. Feeling good, in a sling, not much pain.
After a lot of internet, got the Rogue cambered bar for squats and good mornings, a Rhyno harness for front squats, and two different shoulder straps (Spud Inc. and Repel Bullies) for deadlift variations. Did a trial run 3-day HLM before surgery, subbing dumbbells for the upper body stuff, modeled on Andy Baker's GGW. Made sense to drop down to the 65-70% of 1RM range to get used to these unfamiliar--to me--lift variations. (Took 40% of upper body barbell lifts to estimate 1RM for dumbbells.). Went okay, weight estimates were reasonable. Got a cable set up for doing some light arm stuff one I get the okay.
My surgeon does not seem super conservative: no splint, expecting to start light rehab after my post-op visit in eight days, said I can start lifting after 3 months. Going to ease into it, use it as an opportunity to learn some assistance variations I can incorporate into my routine once I get back to the big four. Doing a lot of reading, watching videos by people that went through it, and making a plan has really helped. Feeling very positive despite the setback.