The primary reason for -not- offering service in any given country is, primarily, regulatory (see the South Africa case). Once they
We operate several of these in Kenya:
https://x.company/projects/taara
They offer 20 Gbps at distances of 20km, and they operate under considerably more vibration, motion, and scintillation than you have in space. They have no issue keeping track of each other once initial acquisition is made. SpaceX launched 10 satellites into polar orbit in Jan 2021, which it used to test and characterize the ISL optical heads - you could see them positioning the satellites in configurations to test side-looking (thus cross-plane), and at different altitudes (cross-shell), and even parallel links to characterize hardware differences (we did this with ours in Kenya too). It was fascinating to watch. I’m quite certain the least problem for Starlink (unless they made major boo-boos in hardware or software) is acquisition and tracking.
A very good book (but not cheap) on the topic is "Free Space Optical Communication” by Hemani Kaushal.