Unfortunately (at present) Starlink does not provide for mobile platform access. They say you have to stay within your access cell and people have reported inability to connect if the antenna is taken somewhere distant from the registered home position. Maybe that will change in the future though?
There are two approaches to mobile users. Either you have a beam from the satellite directly track a moving user, or you have many fixed beams from the satellite and the user has to jump from one to the next as they move.
The first method was definitely used to begin with, but it doesn't scale - the satellite only has a certain number of beams available, so past a certain number of moving users it becomes necessary to use the 2nd system, which requires a very different software setup.
Eventually a hybrid system might be used, allocating per-user beams to the highest bandwidth users at the time. Per user beams can be far narrower and therefore get better SNR and more data throughput.
Moving users do not make a difference as the relative speed between satellites and users are dominated by the speed of the satellites which is kilometers per second vs. kilometers per hour for a moving user.
The Starlink dishes and satellites are using phased array antennas by the way which can steer the beam extraordinarily fast without having to physically move the antenna at all.
The beam steering takes about 10 milliseconds. That means effectively the beam can't be steered at all during use (imagine you steer the beam to one user, send a few packets to them, then steer the beam to another user, send a few packets to them, and repeat - thats a 20 millisecond jitter the users incur - completely unacceptable).
That forces the beams to remained trained on a single user or area (covering a group of users).
OneWeb is coming to boats this year, even before it has global coverage. One thing to note with OneWeb is there are two terminals that must be placed more than 10' apart. e.g. ideal to put one on each hull of a cat, might be a bit tricky finding somewhere to put them on a 35' mono-hull.
So far it looks like OneWeb is going to be a better option for marine use because you can actually find information about it within the industry already. With Starlink all we have to go on is speculation and the occasional tweet.
One of my sailing channels I follow YouTube once said - it's not really cruising channel, it's a bluewater boat maintenance channel. Those episodes are always the most interesting!