re: flash memory: even with 2MB flash, the firmware upgrade can still succeed, but there will be issues, most likely it never goes out of AP mode. Since yours is connected to your WiFi, I assume yours is 4MB flash. I should probably update the firmware to include the flash memory size as a controller variable or debug variable.
As I said, once in a while it may stop responding to ping, but it should recover after a while. Does yours stop responding and never recover? I am not sure what the openhab integration ping does, I can run a javascript locally to ping on a regular interval. When the local IP stops responding, does OTC API still work? I know the beta version had a problem where it can lost local connection permanently. I’ve fixed that issue in the OTC library so firmware 1.2.0 shouldn’t have that issue anymore.