ESP-NOW network with 2 WiFi gateways

[raiukan]

Would it be possible to extend this ESP-NOW network scenario to allow for two wifi gateways (i.e., two Access Points going to two different wifis)?

I'm installing ESP32s on train cars. The engine has one ESP-NOW/ESP-WiFi gateway node hooked up to a laptop, the train cars behind it have plain sender/receiver ESPs, and the caboose (1/2 mile away) has the other ESP wifi gateway node. This is so the train cars can be changed out, rearranged, etc, but still allows the engine and caboose to communicate to each other, bi-directionally. Sort of like a bi-directional mesh network with two access points.

Is this feasible with ESP-NOW (probably not since it requires pre-known MAC addresses), or is there some other mode that would suit this task better?

(Note: I've tried setting up an ESP32 meshnet having multiple APs, but the mesh fragments into two networks that don't see each other. I've been told: "Due to hardware limitations, the mesh can at most connect to one AP".)