Nasomi tweaked FFXI to run specifically for Nasomi... which is different from the other private server. You could probably get it running but you can run into errors sometime in the future which only YOU may have and no one else. Play at your own risk.
When you first had the problem with Nasomi did you use Nasomi installer or the other server installation ? Either way the point where the issue of it closing on your first attempt could be solved using this Ashita
https://na.nasomi.com/software/Ashita.zip Try it next time if you come across the problem again with a Nasomi installation of FFXI. Don't use the ashita that came with the installer or in the torrent.