As per synology's website it is execute with high privilege, ive used that for multiple instances as well, including your (binhex) delugevpn. But pia told me to use qbittorrent instead as it would be better for speeds.
Ive tried multiple changes among vpn_enabled to no but no different out ome unfortunately.
I thought it had something to do with VPN port forwarding but that would be weird as I should still be able to access the we ui even when VPN is off