As for the "painful adjustment" the only variable you should have to adjust is the fore / aft position as this is the only one strictly dictated by the regulator mounting.
You've shown by this comment that you don't really understand how the adjustment process works at all.
Once this is set you will have to slacken and tighten the two mountings at the bottom of the glass whilst it is hard up against the stops to ensure that it meets both stops at the same time.
No, no, no.
First of all my credentials
The two mountings at the bottom are nothing at all to do with the height adjustment. Nothing. The nuts at the bottom of the glass are the adjustment for rotation and longitudinal position. It is the nuts at the top of the door frame that adjust the height stop and that is the most trivial adjustment of them all.
Of primary importance is the tumblehome trajectory adjustment. If you don't get the tumblehome trajectory right in conjunction with rotation and longitudinal position you will NEVER get an airtight seal with the window.
If it was as easy as you make it out, why do you suppose AR devote 8 pages of the workshop manual to the entire process ( including door alignment checks ) and went to the trouble of making a special tool ( 1.823.030.000 ) to do the job properly?
The correct steps are :
Set the fine tumblehome adjustment to the default position
Adjust the coarse tumblehome trajectory
Adjust the height stops
Fine adjust rotation and longitudinal position of the window.
Repeat the last three steps until the window is correctly positioned.
Recheck everything and start again if necessary.
When complete, set the up/down trajectory arm position.
If necessary use the fine tumblehome adjustment.
Adjust the autodrop system if fitted.
Yes, it is a painful process to do properly.