Sure you don't want to use them outside their rating.
But if you buy pressure PVC-U parts which are especially made to be constantly used with pressures of 10bar (145PSI) and you just use them with 60PSI they should be totally save. But as said it should be the right tube not some random PVC pipe. I got mine from a pool supply store in Germany.
But you are right if you use something you don't trust, put it in a bag or wrap it with tape or fabric.
When I did some pressure test above 15bar with a PP tube from the hardware store (not rated for pressure) I also capt it in a bag... so it was safe when it finally blew up after a while...
The bottom line is don't cheap out on a cheap alternative... there is a reason when the alternative to a 350$ solution costs you 10 instead of 5 bucks