This should not be necessary, nor is it a particularly desirable way to start XCenter.
It is the only way to start XCenter, without messing something else up, on every ArcaOS system that I have (as well as with eCS, and warp 4). If I let XCenter start itself, About 20% of the time, something else (random) fails to start later. If I start it in the ArcaOS Startup Folder, after a 3.5 second delay, I don't see those problems. I am pretty sure that the problems are not caused by either XWP or XCenter. You do need to turn OFF the setting to start it automatically, when you start it in the ArcaOS Startup Folder.
OTOH, if it is checked _and_ it consistently fails to open after a reboot or restart, please advise so I can investigate the problem.
I consistently see XCenter fail to open, on two of my systems (even after the 3.5 second delay), if I let the system make an Archive. It just hangs starting XCenter. CAD causes a reboot, and then it is okay (not doing an Archive). One other system fails to open one of the programs, started in ArcaOS Startup Folder, after doing an Archive. The symptom is exactly the same as not having the executable file present when you try to open a program icon. After the system starts, without that program, I can start the program manually.
There is a problem, for a very short period, as the system starts up, that seems to prevent finding files. Changing the startup timing can make that happen, or get around it. It all depends on exactly what is going on when the problem occurs. It is also an ancient problem, that has never been fixed, and, it is one of the main reasons why the ArcaOS Startup Folder even exists.