Due to space constraint electrician installed the 2 switches depicted in attached photo.

Is anyone aware of another solution to remote control these using an Insteon compatible remote button? I could use 2 of Insteon's toggle remotes, or one of their scene mini remotes elsewhere in the space, but I need to insert something into these switches which control 2 sets of on/off lights, both with multiple fixtures inline.

2 Insteon micro modules won't fit inside box.

Depends a little on the wiring, but the micromodules could possibly installed at the destination fixture instead of in the switch box. See the manual, page 5. You'd install it at the first fixture in the case of multiple fixtures on one swtiche

Thank You @paulbates that is clearly the logical solution I was not seeing

Yes I believe I'll have room in the boxes in the ceilings that the fixtures hang from. Thanks again

If all the fixtures are wired together you can you put the inline module in the first box fed from the switch.