good to hear. you need to sandwich the 'stat probe between the UTH and the bottom of the tub. if you have one of those adhesive/stick-on UTHs, VERY VERY carefully peel back a corner and shove the probe in. they are very easy to damage during removal so just be very careful.
for my thermostat: i have it set at 95 to get the floor around 90. you need to figure out what works for your setup. i think i recall you ordered a temp gun? use that to dial the thermostat in. it can take a couple hours for the UTH to finally start having a stable temp once regulated, so just be patient.