I always homeruled the same thing at my table, it has never been an issue luckily.
"I didn't notice the issue" is not the same as "It's not an issue".
There's a reason if the official material warns every DM strongly against these types of homebrew
:
- allowing more than one spell per turn in almost any circumstance (I think Action surge is the only real exception?)
- ever offering more than a bonus action
- allowing more than one concentration spell at the time.