Intermediate Wet and Full Wet Tires

Tires in IGP arn't at all on par with racing tires today, not just pirelli, but other suppliers. Right now Wet and Inters do have a determinable mm of  water usage but it's not specified for other drivers to use. Wet races are uncommon, but not common enough to learn how to use them properly. Rather than this being 'to find out' it would be a good idea to specify the mm required for operating these tires, especially for those who are struggling when it's wet.

But how would iGP defining the requirements help when we do not have a way to track the amount of mm of rain on the track, at any given time.

Pretty sure in the Real F1 they just look at laptimes, and see what everyone else is doing, and make their judgement from that, same as what I and maybe others do on iGP.

Although nowhere in the race does it tell you the "mm rain" on track