2020 i7.
Installed 64GB (32x2) G.Skill kit F4-2666C18D-64GRS. Works perfectly. No need to buy specially labeled “Apple RAM.”
Security Torx, you can stick a 2mm flat blade screwdriver in the head and twist. The center pin will snap off clean. Regular Torx then fits perfectly.
While it was apart, I replaced the heatsink paste with Coollaboratory Liquid Metal Pro. Also used thermal epoxy to attach a 2mm thick copper shim across the top of both heat pipes. This adds thermal mass to the heatsink assembly, which buys more time before max temperature. It also helps distribute the thermal load between the two heat pipes. Added over a minute to boost clocks before throttle using Intel power gadget. Stable, throttled average clock went from 3.3GHz to 3.5GHz. Did not test liquid metal and shim separately, so don’t know which mod had more effect.