If both site could same subnet on PepVPN

I would like to ask if both site could same subnet on PepVPN.
If yes, if there is any problem?

Yes, using L2 Speedfusion our router will behave like a bridge.
Possible concern will perhaps be the bandwidth, as there will be overhead that you need to consider.

May I know if both site we select Override IP Address when bridge connected “Do not override”,
and we set both router are same DHCP range, will it deliver the same IP on both router and caused IP conflict?
i.e. we need to set different DHCP range on each router.

The host site (bridged over to the remote) should be set to “Do not override”. The remote site would be set to static or DHCP for the web management address when the VPN is up. The host side is the only DHCP server providing IP addresses to clients on the remote side.