Using a clear filter to protect the lens is a practice I follow. I have also considered the other side of the argument that putting another piece of glass in front of these high quality lenses could reduce the quality of the photo ever so slightly.

My solutions are:
1) To remove the lens cap by unscrewing the filter still attached to the cap. When my shooting is done I simply screw it back on.

2) Using a quality filter over a cheap one to minimize any loss of quality.

Rarely, do I take the filter off but it is an option.
If you do as you say, get a metal screw in cap and you will well protected without having to buy a filter. Been doing for decades.

Happy Shooting!!

Dodie