Please be aware that constantly retuning / re-tensioning a regular, good-ol-fashioned wood bass is rough on the bass and the strings.
Constantly retuning through dropped tunings and standard multiple times a day can be tough.
I thought I retuned a bass more than anyone in the world with all my odd-tuning jams and songs, but it sounds like you’ve got me beat.
The ideal solution is: get another cheap bass, and leave it in the lower tuning.
Same for a 5 string.
It’s so lovely and comfortable to have each bass set up to play well, keep constant and regular tension on the necks, and be ready to go when you want it.
My 2 related stories:
In highschool I played in a metal band that tuned down a fourth (BEAD) but I also played normal stuff and took lessons, and I only had one bass. I had massive strings on the bass (to sound decent detuned) and detuned and retuned regularly. The neck got JACKED. It was warped, as well it should be after all that abuse.
The bass I did my most bizarre tunings on was a Modulus which had a graphite neck which didn’t care what you did to it and always stayed in tune. So that worked out.
The multiple bass solution is the most versatile and convenient (and labor/cost effective) in my opinion.