[mfranc42]

Yes. People keep repeating this and while it is a real problem for some designs, most professional cameras allow to bypass it with a remote trigger, often an official one.

Besides people were doing long exposure since like forever with great success. If the sensor overheating was a problem, it would make sense to introduce a hard limit and some cameras have them, but from my experience the likely reasons for the prevalent 30s are: 1/ most people don't do several minute exposures 2/ they need to sell remote triggers to somebody.

30s limit was there even during nineties when you could do hours on film without overheating anything.