I have been heavy dosing magnesium (glycinate, citrate) for years and am still a nervous wreck. Your mileage may vary.
The L-Threonate compound was developed at MIT specifically for better brain absorption. Source: https://dspace.mit.edu/bitstream/handle/1721.1/96066/Slutsky...
I've always been a slow morning person, so 30-60 minutes to start feeling normal is on par for me, so it doesn't really affect my timetable, but you may have a different schedule in mind.
My morning bowel movements when I take magnesium l-threonate are amazing, however, which used to slow me down even more on a typical morning.
The stack: https://www.facebook.com/StrengthSenseiInc/videos/anxiety-so... (sorry for FB link)
Background on Poliquin: https://tim.blog/2015/07/21/charles-poliquin/