They are adjustable within a range:
Front Height Adjustment: -25 to -45mm
Rear Height Adjustment: 0 to -50mm
Front Spring Rate: 42.6 N/mm
Rear Spring Rate: 116.8 N/mm
The language is usually written such that your warranty is safe provided you are not in a "timed competitive event".
I haven't seen the exact wording from TUSA but that's what I recall from the BMW M car warranty.
It should be explicitly stated in your car's warranty booklet.
I agree Option C, especially since BMW has confirmed the G series M3/4 will have a manual transmission available.
Otherwise, I suppose a manual transmission would be my first pick. We can always look to the aftermarket for a bit more power.
I bet this is a coding issue. If recall, before it was enabled by default, the 2015ish BMWs could be coded to "remember last setting" for the auto stop/start.
I would assume that can be coded back in on the Supra.
EDIT: Looks like I failed to refresh the page before replying!
I have a lead on a sunshade with Covercraft, but my car doesn't show up for probably another three weeks (at least) to confirm fitment.
Part Number is UV11646 for the 2020 Z4. Photo is the image I was provided.
Covercraft uvs100 has been my go to for years, but it looks like they don't have anything on their website yet for the Supra or z4.
I haven't contacted them yet to see if they plan on making one.