Yeah, depending on your instrument shape, the "normal" U shaped guitar stand isn't ideal. If you've got something asymmetrical, they can be a pain, and the stands where the bass hangs by the head might be your only way to go. Find something that fits your bass, doesn't bust your wallet, and folds down so it's easy to get from point A-B. I played in a band where it made sense for us to have a rack on stage because the guitarist and I had way too many instruments up there. Those were the days when I'd play two electrics in a night, acoustic guitar for a set, and electric guitar if someone absolutely needed to hear Takin Care of Business. Dark times...
I try to bring as few instruments out on stage at a show as I can. Switching basses can be really stressful in the moment, you have to really know your output levels and amp well or have extra gear so you can A-B settings. This is especially true between an electric and a double bass, as they are often hugely different from each other. One of those cables with a kill switch on it or a mute pedal on your pedal board can help, but losing the first bar because you forgot to turn back on again makes you feel really stupid. I found that even if I really though a P bass sound would be great for a couple of tunes, it isn't worth the loss of momentum in a set regardless to how quick I tried to make the change happen.
On double bass, I've done recitals and concerts with multiple basses and bows as well. I played a program where I used Viennese tuning and a period bow for one piece, and then my regular bass with two different bows. Again, the audience was distracted by the changes, and it turned into "why did you play so many different instruments/bows?" and the benefits were largely lost on an audience that was more focused on "that's not what he played on in the last piece" than what I was doing.
If you're in a musical, big band, or a setting where you've got some time between tunes, it gets a lot easier. If you're playing multiple sets and you can play one instrument for the whole set, again, it's less of a headache. Those kind of shows, I will bring multiple instruments if needed. Sometimes the colour change is really fantastic. I've just seen "wow, here comes the double bass for that awesome ballad" turn into "too bad we couldn't hear it because the bass player forgot to adjust his amp".
If you need to, it's in your contract, the gig really requires it etc. then sure, bring a whole family of basses along. Until I am in a situation where I've got serious money to burn on multiple basses, and a guitar tech running on stage with my next instrument, I'm keeping my setup as simple as I can.
