I'm going to have to revise my statement about the product in the OP. I think it makes more sense on a first gen and none sense on a second. Here's why.

I have been tinkering about with the rear sway bar on my second gen. The bushings mount on the opposite side that the first gen does. When you unhook the endlinks anh rotate the bar level with the ground on the second gen, the eyelets for the endlinks overhang the RLCA by quite a bit. This product would exacerbate that by making it overhang more. I would surmise that it gives the bar less overhang on the first gen.

Then there is the issue of space. This product has a 20mm offset. There isn't much past 20mm from the top hole on the second gen mount.

I could be wrong but I believe the sway bar eyelets on both setups have an equal amount of overhang relative to the RLCAs. The centerline of the sway bar should be the same on both 1st and 2nd gen. I think a 2022 brz and 2022 gr86 can use the same sway bars.

Also this part will for sure not fit a 2022 brz as your setup doesnt have the required 3rd hole for the oem bracket's "hook" to slide into. On your setup, that hook just wraps around the bottom of the mount itself. The 2nd gen sway bar mounts are easily 20mm shorter as you mentioned.