@Zyxel_Charlie: Any updates here? We expirience even worse issue with USG20W-VPN, having only 32 PTR A-Records available, which is by far not sufficient for save professional operation even in small teams. Please let the customers to add more A-Records, i.e. 256, on DNS Page. This should not have any performance drawbacks…
Thanks, I've solved the problem, adding an additional Policy Route on Office USG which redirects all traffic comming from VPN Home users towards customers destination to Customers VPN using its tunnel as a "next hop"