Will Beta update itself to release version, or will I need clean install again?

That is the question. ))

Based on experience with other products, I can say it probably would update.
But it is always suggested to make clean installation.

I would strongly advise an uninstall and re-install.

Best wishes

Mouse

However, Comodo may decide in the testing process to provide an update also by the program updater for testing. In that case make the choice you feel comfortable with.