Heat isn't really the primary concern here. The big risk is vibration. The sound waves from 33 engines firing at once are enough compressive force to literally break apart steel.

I saw on one of the space blogs (that I'm too lazy to find) that they brought massive bags of super-strong concrete (refractory cement?) for the pad after the last damage, and those bags disappeared so it was assumed the new cement had been used, but they were later spotted elsewhere at the facility, so there was some conjecture that they may have used standard cement again and doing this knowing it is a sacrificial pad. So don't be too surprised, or too concerned if the pad is damaged - the fancy cement is on site.

Pad can take it it’s got diverters I’m more worried about things that are meant for air flow for cooling. Assuming test is time limited.