Depends on the type of rack and temps anything below 75 you definitely want to look into enclosed racks vs open and even than you might have to consider having a oil filled heater plugged into an reliable external thermostat.
I have enclosed racks in cooler months I run a oil filled heater set on 75 so the ambient temp on the cool side is 75/76
enclosed would be the route I would go for sure. So basically I was right in my thinking that the heat tape isn’t going to effect the ambients inside the rack much, if at all?