I discovered while deploying some fighters that I can still stack things, albeit in a much more random fashion now.
If when I click to deploy the ships remain highlighted as if I was going to move them, then I can click again and a second set of fighters was deployed. I found I could (if I tried) stack about 3 squads before my clicks didn’t select the group while also placing it.
I have this problem whenever I use the mouse buttons on my laptop, if I use a hardware mouse though, the clicks register correctly, though I have a suspicion I could still duplicate this if I tried with a hardware mouse. I shall attempt to do so and report back.