You are welcome and thanks.
Now that I am home I can find the datasheets I mentioned, I hope the upload system handles them well.
Anyway, these are DB datasheets for the MW50-less DB 605A and the MW boosted 605AM. Otherwise the engines were exactly the same. They give the following data for heat generation (see the middle, 'Abzufuehrende Waermenge' - or something like heat to be transferred/dissipated/carried away)
1) For the 605A (no MW, powering G-1 through G-6) the maximum heat generation was 340 000 kcal/h at the critical altitude, this is understood for 1,3ata / 2600 rpm 30-min output, which is 1250 HP (PS) at 5,8 km.
2) For the 605AM (MW boost, powering the G-14) the maximum heat generation was 345 000 kcal/h at the critical altitude, practically identical, but this is understood for something like 450 HP more produced 1,7ata / 2800 rpm 10-min output, which is 1700 HP (PS) at 4,0 km.
So for all practical purposes, MW cooled the engine enough that coolant system did not have to cope with more heat while generating 1700 PS than when it generated 1250 PS without MW injection. And as the previous post's engine temperatures showed, the 109G coolant system easily coped with the latter even in climb at around 270 kph IAS.
In short, the coolant is very likely next to impossible to reach critical temperature values in the G-14 and its reasonable to say, in any other MW boosted variants, since they had similiar output of 1800 PS, except the 'C-3' 1.98ata K-4/G-10. In addition, the high altitude variants, ie. G-6/AS, G-14/AS, G-10 and K-4 had larger radiators than the previous 109G - see previous posts again)
Oil temperature can be a different matter, since as the data shows the 605A 65 000 kcal/h at 1.3ata while the AM 96 000 kcal/h at 1.7ata. Though here it should be mentioned that the MW boosted 109 typically had larger oil coolers as well (the G-14 is actually the only exception, since in some cases it retained the older oil cooler, the later and high alt models all had larger ones).
I hope the above information is useful for the developers to create an accurate overheat model.