Miata Turbo Forum - Boost cars, acquire cats. - Weird (?) coolant temp fluctuation

Apologies for the 6 year thread revive (better than starting a new thread on the same topic) - were you able to get to the bottom of this?

I'll start with I know boost control needs tuning.
Status 5 is setup to monitor CLT ADC counts.

Does the CLT rise/fall rate shown in the first image below seem pretty normal of a turbo setup? Maximum rise rate is 6°C/sec and fall rate is 4°C/sec.
Max delta of 3°C while NA seems ok, how does 8°C for a turbo setup fare?
Interestingly it is most evident from the last WOT pull that CLT begins to fall while WOT is maintained for another 1 second.

FMIC is 1.5" away from the radiator with no ducting, only an LRB undertray is used. Coverage is most of the radiator laterally and up to the bottom of the hood latch vertically.
NA setup only differs by having a thermostat installed (Thermostat was removed during the turbo log to remove a variable when troubleshooting overheating - hovered around 110ish °C at some point).
Cooling system includes new water pump, kia reroute and supermiata rad. Turbo water lines were also temporarily removed for the same reason above.
ARP studs and OEM gasket since it was mentioned above.

Turbo:

https://cimg4.ibsrv.net/gimg/www.mia...19d5ec4ba7.jpg

NA:
*Status5 would have been monitoring TPS here

https://cimg1.ibsrv.net/gimg/www.mia...907c5d3811.jpg

Appreciate your input, thanks.