Goodsync or SyncBack Free/Pro with my Synology Workflow ?

Hi everyone, I'm currently creating a 321 backup workflow for my NAS and I'm using this workflow :

1. I run a couple of jobs with SyncBack Free to sync 2-3 shared folders to my external drive(drive #1).

2. That external drive is then sync to an another external drive (drive #2).

3. I use Backblaze to backup that second drive (drive #2) to have my offsite Backup.

I saw that there's a Goodsync package for my DS923+.

Is there any avantages to install Goodsync directly to my Synology ?

Anyone is using their GoodSync connect feature too ?

I'm trying to determine if I should buy GoodSync or Syncback Pro to sync my stuff or if I should stick with the Free version of Syncback ?

Thanks for your comments :P