This is annoying and something had to be done in my opinion. The "follow race strategy" and "unschedule stop" boxes are doing more harm than good. For instance, if you want to pit your drivers for a different compound tire change, i.e. when change from rain to dry or viceversa, you have to uncheck the "follow race strategy" box and check the "unschedule pit stop", enter the fuel amount and select the tires from the tire menu. Do this for two drivers, while calculating the fuel needed, since all strategy will have to change and you are very prone to get a mess.
Even so, I did that, but when I had to pit again, on my last lap before pitting, I selected 48 liters of fuel for both drivers, then the PITTING light switched on and drivers switched automatically to their before-race planned 32 liters, even though I specifically told them to take 48. This is stupid. I radioed them and told to take 48 and they took 32, like planned. For this, I had to do an extra stop and lost a 1-2 position in the end.
So, if you plan to do an unscheduled pit stop, even though you tick the box and select the correct fuel, if you are unlucky to have the PITTING switched automatically before you tell your drivers to pit, you are screwed. All you entered before is erased. I love wet races... NOT !
First of all, you didn't necessarily lose a 1-2 ;) - There's every possibility that I would have been with you, because 16L of fuel can account for a lot of pace. Although I can sympathise with you that it doesn't always work. But that's why I always do the unscheduled pit part AND the next stint part, just to make sure. That way, I know it can't go wrong.
The pit strategy window does need a redesign. I'll nudge that up the priority list.
For the time being though, there's a closely related task already on the development list that I'll try to get done asap. That is, to have the automatic weather strategy modify the options selected in the pit strategy window so you will see in the Next Stop row what work will be done to the car. Also, any changes you make from that point onwards will overrule the weather strategy. So once I get that done, you should at least see more clearly what is going on, and be able to "radio in" to overrule.