I have some general questions I would like some details if possible

1) I'm installing several veeam infrastructure and very often architect ask me to use 1 proxy / host.
I see this is a recommended for hot add mode but I don't find anything about NBD. I often use NBD on 10GB network and I can't use 4 task or more on each proxy because there is only 1 repository and he can't handle 20 or more proxy tasks.
I would like to know how do you manage it ? Is it good 1 proxy / host on NBD mode ? How do you do to manage task with proxy and repository ?
2) I'll have to backup to apollo xfs (SOBR with 2 200TB repo) and immutability the vmware infrastructure and I have NAS backup to (arround 80To).
I saw immutability is not possible for NAS backup but I suppose I can use it as repository target but data will not be protected right ?
If I want to use archive for NAS, I see I need to create repository because SOBR can't do this.
3) What happen if I use GFS on backup job and I have backup copy job too for this job ? My GFS points will be copied to the backup copy repository and that means all the full backup will be sent ?
I will have other question probably but I don't have them in mind now :p
Thanks for your help
