Removing the tape and PE would probably lower the volume almost as much as going to quieter switches. YMMV though.

also the ping. Had one (non-HE) for a bit, was really disappointed with how it sounded compared to how good the finish and overall machining quality was.

More to the point I wasn’t saying they were good options, just that they’re non-Wooting, non-tray-mount HE keyboards with rapid trigger that appear to be functional enough from the bits of information that I can extract from random non-English reviews, which bodes well for the Q1 HE whenever Keychron finally get it to market.

Unfortunately, all of the Hall Effect (magnetic) switches out there are linear, so no.

The Monsgeek M1 HE and its pricier sibling the Akko Mod07 HE are out for couple months and appear to be functioning well enough, from what little I can piece together. Not QMK admittedly.

I suspect the gaskets won’t affect the Hall Effect sensors at all as long as the PCB and plate are screwed together tight enough, since I think they’re only sensing the relative position of the switch magnets to the PCB.