Here are a few possible combinations.
The power supply tray can be mounted to the underside of the modules, and a patchbay can be mounted to the left or right (Ascend 36) or left and right (Ascend 48).
Two Ascend modules can be connected to each other using the Ascend connector set.

A36 & A36 (72 cm width without side handles)
Handles can be mounted on the sides, which also serve as kick protection for cables connected to the patchbay.
Only Lift 36 fits on Ascend 36 as a second level – unless two Ascend 36 modules are connected, in which case Lift 48 can also be installed (aligned to the left or right).

A36 & L36

2x A36 & L48 (installed on the left here, can also be installed on the right)
Ascend 48 is compatible with Lift 36 (left or right aligned) or Lift 48.

A48 & L36 (installed on the left here, can also be installed on the right)

A48 & L48
Flat modules are not compatible with the power supply tray or patchbays.
However, patchboxes can be mounted on the surface (including under the upper level) – mounting holes are already provided for the Duo and Trio patchboxes.
Handles can be mounted on the front or back of the surface – if one is mounted at the front and the other at the back, the pedalboard is balanced when lifted.

F54 & L36 (installed on the left here, can also be installed on the right)

F54 & L48