The issue is one of timing, since "OG" is defined as the gravity at the time of the transfer into the kettle, any gravity additions after that point aren't counted in the OG, but should be counted in the ABV formula. However at this time, the ABV is a function of the OG, and the FG, so your abv with any Late:Fermentor aren't being counted properly. This will be remedied.
However, the apparent attenuation of the sugar additions are counted towards the expected FG.
Kettle addition: (There's a bug here, the fg should be lower, bringing the abv up 0.2ish to match the fermentor vs no sugar differences).
Current Fermentor addition: (Almost the same as the no-sugar addition, but higher attenuation drives the FG down slightly, raising the abv).
No sugar addition:
After the update (approximately)
OG: 1.089
FG: 1.007
abv: 10.70
2) What I was referring to is that if you add 2.5 kg of sugar at 254 "points" to the wort. If you add these points to wort before losing some of the wort, then you're also losing some of the sugar points. VS adding it into the fermentor, where you will "keep" 100% of the sugar points so to speak.
Example to keep the math easy:
5 gallons (20.82 L) postboil volume, add 2 LB of sugar (0.91 kg), ie 92 points bringing the gravity up from 1.060 to 1.0784. If you then lose half a gallon (~2L), then you will also leave behind a corresponding percentage of that 92 points, or 9.2 points. The gravity doesn't change from 1.078 during the actual transfer, but if you would have added the sugar afterwards, then the you would have 1.0804 since the sugar was added to a smaller volume.