PVC and Heat Tape

[Homebody]

Should I put the heat tape on a pulse-proportional thermostat as well, or will the on/off thermostats I'm using in my current setup (for CHE and heat pad) suffice?

I've been regulating my heat tape with an on/off thermostat for three years. No problems, though I'm using the tape to heat a tub and not a pvc enclosure.