Accurate Strong Gantry

[vargai]

To get the best rigidity you need to keep the spindle inline with the support bearings so no overhang.

Hope I understand well. I made a top view sketch (left figure) -I think the spindle can get much closer to the posts.
The higher H gantry beam is agreed.
Ideally it should be balanced like a VMC in the right figure- manufacturer apply 500-600 mm and more overhang without problem.
Theoretically a reversed moving balance can be done but it increases the mass on Y axis motor
There are tasks left.