Overheating Issues

I’ve been having overheating issues for years only in the summertime(90+ deg). Not exactly sure when it started or if it’s always been like this. Just wanna get some thoughts on possible reasons. It slowly overheats when ambient temps are above 90 and you’re either idle, going uphill, or heavy on the throttle. Temps rapidly decline when going downhill. The fan is working. I bled the coolant a month or so ago. No leaking coolant. No coolant in the oil. AC blows cold still.

When it does get hot I switch the heat on to lower the coolant temps. If not mitigated it can go into limp mode with coolant temps at 240+.

2017 Mountune package with Mountune triple pass radiator, cpe intercooler, hollowed cat straight pipe, Mountune mrx turbo kit and piping, and stratified 93 pop tune.

If you have any ideas to what the problem is, I’d love to hear them. Thank you.