Qdog. There are many different types of induction cookers with varying methods for controlling temperature. In general, the numbered control mode is really erratic and inappropriate for cheese making. Temperate mode can work depending on the induction cooker. Our main cooker can only go down to 140F, but we use it every day. I have another cooker that goes down to 100F with 10 degree increments - 110, 120, 130, etc. I actually use that cooker for sous vide style cooking and I find that it will hold temperature to within 2-3 degrees, IF you don't put the lid on the pot. With the lid on, it can vary 8-10 degrees. That's because induction measures surface temperature NOT inside the pot.
I would strongly suggest that you try to use a double boiler - pot-in-pot - setup and stir frequently to equalize temperature. Before you add the rennet, the induction cooker MUST be turned off. Otherwise you will be adding excess heat to the bottom of the pot and the milk.
A 7-8 gallon make is 60-70 pounds and an awful lot for an induction cooker. If your pot is hanging over the element you can get uneven heating.