JGalt has pmed me more info about subsequent track day temps that he may wish to share
What I noticed over this past weekend on my '07 Exige S, stock dual-cooler set-up:
Dry track, 80 F ambient, BOTH oil cooler inlets covered: 205-207 F oil temp in pan
Dry track, 60 F ambient, BOTH oil cooler inlets covered: 185 to low 190's oil temp in pan
Wet track (standing water spots), 50 F ambient, BOTH oil cooler inlets covered: 165-170 oil temp in pan.
1) covering the inlets is sufficient for summer (like) days where engine can be fully rev'ed to generate plenty of heat (meaning dry track).
2) colder days, like summer morning track sessions OR in rain, where for the latter you gotta stay a bit lower on the rev's, oil temps are less ideal
3) clearly there are disagreements on this thread and across the internet as to what oil operating temperature is best AND for what reason; my goal is to always be at or ABOVE 200 F without being above 240, both on the track and on the street WITH the smallest investment and least changes to OEM set-up. That's my personal preference.
Right now I'm headed towards testing the Mishimoto with 200 F thermostat and using the OEM dual oil coolers.