storage passthrough in vm & access from LXC - performance questions

[droptables]

Task: figure out the best performing settings for the following scenario

Setup:

• Proxmox host with dedicated mgmt NIC (VLAN 200)
• Mellanox Connectx4 SFP28 connected to Mikrotik CCR2004 (10gbps WAN)
• Openmediavault VM (2 interfaces: VLAN 200 for mgmt interface, VLAN 20 for SMB / NFS) with NVMe pcie passthrough & hdd virtio passthrough
• Unprivileged LXC containers that need to access the storage VM & internet

Most promising solution:

• NFS shares to PVE host
  • https://forum.proxmox.com/threads/tutorial-mounting-nfs-share-to-an-unprivileged-lxc.138506/
• vmbrX network between VM & host (local only)
• script to mount NFS shares at startup to PVE host
• delayed startup of LXC containers

Questions:

1. what is the best approach to mount the NFS shares after the VM has booted as it they won't be available at PVE startup (VM booting takes some time)?
2. what is the best approach to delay the startup of the LXC containers and make sure that the NFS shares are mounted to the PVE host?
3. has anyone a similar setup running (I didn't find it on the forum, some people have the pve host & vm on the same subnet, that's not an option)?
4. Any other suggestions?