Boil Off Tool: Scratching my head

I'm trying to understand the Boil Off Tool in BS2 v2.1.02, either I'm stupid or the tool is counterintuitive.

Starting volume: Is this the expanded volume measured at boiling temp?
Starting gravity: Is this measured at 20C or something else?

I have enclosed an example, where I assume the starting volume is actually measured at 20C, the same is true for the post boil volume.

The formula V1 * GP1 = V2 * GP2 gives me 30 * 100 / 27 = 111, all fine and dandy.

Now if I fiddle around with the shrinkage rate, the post boil gravity increases, is this correct? I thought the formula above needed the temperature before and after (1 and 2) to be the same? As I interpret it, BS2 is mixing starting volume at boil temp with post boil volume at chilled temperature.

Edit: If the calculator is indeed using starting volume (V1) measured at boiling temp, shouldn't the formula be something similar to

V1 (Boil Temp) * 0,96 * GP1 = V2 (Chilled Temp) * GP2?

You are correct.  BS2 is pretty sloppy about mixing measurement conditions for volumes and gravities.  That's why I do all my own on paper.  I've even added tables to my brewsheet to allow me to calculate boil-off and boil-down-to volumes, because you can't trust BS2 to get it right....or more properly you have to guess what conditions BS2 is expecting you to use (at boil, 20C, etc). 

I don't use that tool, but if I did, I would set shrinkage to 0, and input 20C corrected volumes and gravities.  Then correct the final target volume back to boiling temp (*1.04).