John Curtis php 7.4.3 should be fine but make sure that when you switch, the needed php extensions are still enabled after you upgrade php versions. I've noticed that some versions of php change extensions used and may disable one that is needed.
You're welcome. If it doesn't work for some reason, just roll back to previous php version. I am using 7.3 with no issues 7.4.3 shouldn't be much different. You can login to CPanel and screenshot the php extensions currently enabled in case you have to go back or re-enable them upon upgrading.