According to Reptile Basics, pulse proportional is recommended for the most stable temperatures, but it's not absolutely required. Inkbird doesn't make a pulse proportional model as far as I know. It's a lot less of an issue with RHP than it is with CHE, but still aim for the lowest wattage that can heat the enclosure to the desired temps, and do plenty of tests runs till you get things dialed in just right. If you decide to go with pulse proportional, I've had good luck with spyder/herpstat.