I am using an Aleko 1450 very much like the link you show. It is mounted on the side which is quite different from your need. My friend has the same issue you are facing and I been thinking how his would have to work, so I have given a lot of thought regarding a center rail setup for his needs.
However, one piece of information is need from you to see what would work.
1) The rail goes through the roof, running through the center of the observatory, and the front of the rail is mounted to the roof's front. The Aleko motor can be mounted outside or inside by the back wall. Outside will open the roof all the way.
2) The rail needs to be outside due to clearance inside (hitting your head on the rail when the roof is closed). This will require that the motor be mounted outside, center and just past where the roof is when it is totally opened. This will require that another center beam is ran from the rear wall, past the point where the Aleko is mounted with enough beam to hold the rail when the roof is toally opened. For example, a 12x12 ROR would require 20-24 feet of center support beam starting from the outside wall so that the rail which is about 14-16 feet long can ride on top of it.
I would go with #2 unless you have a very tall wall. Yeah, it complicated but its the best way without compromise. No holes in the wall, everthing mounted outside and the Aleko is water protected as designed.
Mounting the track side way along with the Aleko sideway is possible but I am not a fan of this if mounted outside. It would require more water protection for the Aleko box.
I like the Aleko, it is quite and fast. The keyfob is great to have. A scope park sensor can be used to make sure the mount is not going to be hit if that is needed. I am using a magnetic sensor currently for my scope mount park. If you are able, then the relay on the mother board inside the Aleko that controls the motor can be easily modified. The circuit board pad going to the motor relay, its low voltage, can be cut and two wires soldered on each side. Then run these wire to the magnetic sensor switch mounted on the pier. If the mount is parked, the switch will be closed and the pad is reconnected and the motor will run. If the mount is not parked, the switch is open and the relay will not be able to engage.
I am still working on my system, the grandkids visited all summer so work sort of stop. I have changed a few things like starting from scatch the Arduino program, however the basic system is in this post. Once I have finsihed version 2 of the Arduino project, I will post that with the new Arduino sketch.