i have not tested but
laptop needs a static route to 192.168.144.0/24 via 192.168.43.1
companion computer needs a static route for 192.168.43.0/24 via 192.168.144.11
192.168.0.0/24 is an internal network, and i wouldn’t complicate that at this point
you can get rtsp video from
192.168.43.1 or 192.168.144.11
and mavlink from
192.168.43.1 or 192.168.144.11 port 14552
side note, you might not need to do anything on the laptop side, as it will likely be the default gateway… assuming you only have 1 network connection that is to the hotspot.