Not to be pedantic but in my research it was around 6 months in the time between iOS13 and 13.4. That was enough time for me to just move on from the idea completely.The issue with Line 6 hardware was due to an incompatibility at the end of 2019 that involved old Lightning cables and Apple fixed it a few weeks later in a later iOS release. No whims exposed to air from what I saw.
So in short it’s a risk, less of one now with everything being usb c but another example is Adrian Belew had an amazing fx processor on iOS called Flux, I don’t know if you could even get close with a combination of pedals. Flat out just doesn't exist anymore.
I feel I'm arguing against using an ipad as a rig when I did legitimately gig it for several years (I even recorded an album using this rig) and this is long before it was as good as it is now, just if you go down this route there are some risks and you should NEVER update your ipad just before heading off to a gig