Pour info, mon problème a été résolu via une réponse du concepteur de AddOnLinker. Je joins la réponse pour ceux qui pourraient être intéressés :
Hello, NAS are network drives and 'standard' links created by AL (junctions) can not work with network drives. It's an hardware limitation that can not be bypassed. What you can try to do is to change in the options screen of AL (advanced tab) the type of link to symlinks, i have had positive reports that those should work with NAS (restart AL after changing that setting). So if you have current links, remove them and recreate them with the new option to see if that works. As a note, be aware that a NAS will be slower than an internal harddrive, so if you have tons of addons with lots of files you might see a bit longer loading times (AL and sim). In AL make sure the 'enable file stats' is disabled (by default it's disabled) in the options screen if you the loading is very slow, that might improve a bit the loading time. Let me know if that worked out for you. Thank you
Et cela fonctionne donc tout va bien. Iln'y a plus qu'a finir de maitriser toutes les fonctionnalités de ce NAS.