I too only enter the GPS position to align the IRS's

The data for the individual gates would be massive and really makes no difference in IRS alignment for flying in FSX or P3D.

A quick story about the real IRS's...

Wherever your position was at last shutdown of the IRS's was where you needed to be when you would turn them on again.

One time - a long time ago  ;D - I flew into Denver in a 757. Our normal gate was occupied by a "sick" plane so we had to use another gate on the other side of the terminal. During the night the "sick" plane was dispatched and the ground crew moved our 757 over to the normal gate.

Here lies the rub... when they moved the 757, they just pulled it around with the tug. They never aligned the IRS's before moving. The next morning when we arrived at the airport and saw the plane was at it's normal gate, we had no idea how bad this was going to be. When we tried to align the IRS's they would not accept the "new" position since it was off from the last shutdown. It took all kinds of re-sets and manual entries of position using the key pad on the IRS panel before we could convince the IRS that it was okay at the new position 400 feet away.

We would have had a quicker alignment if we had moved the plane back to the arrival gate and done the alignment!

Lou