Can’t flash XS-A18 Plug psk Id 01 - fails to reach intermediate flash

Another 01 psk plug that's been reported to work in the past, but now drops out of pairing mode when attempting to flash.

Looks to be the same issue as
[Can’t flash Aoycocr U3s with psk Id 01
](https://github.com/ct-Open-Source/tuya-convert/issues/825)
[Aoycocr U3S/HYS-U1S-SOCKET-V1.3 not appearing with intermediate firmware](https://github.com/ct-Open-Source/tuya-convert/issues/744)

Board markings are similar to the above - marked as HYS-01-101 V1.3 dated 2019-12-26.

Logs attached. Will be attempting to work out the pinouts and pull a copy of the flash before converting to Tasmota.
[smarthack-mqtt.log](https://github.com/ct-Open-Source/tuya-convert/files/5859911/smarthack-mqtt.log)
[smarthack-psk.log](https://github.com/ct-Open-Source/tuya-convert/files/5859912/smarthack-psk.log)
[smarthack-udp.log](https://github.com/ct-Open-Source/tuya-convert/files/5859913/smarthack-udp.log)
[smarthack-web.log](https://github.com/ct-Open-Source/tuya-convert/files/5859914/smarthack-web.log)
[smarthack-wifi.log](https://github.com/ct-Open-Source/tuya-convert/files/5859915/smarthack-wifi.log)

Start by reading the attached smarthack-mqtt.log, smarthack-psk.log, smarthack-udp.log, smarthack-web.log, and smarthack-wifi.log, then compare the failure with issues #825 and #744. Determine whether the XS-A18 follows the same HYS-01-101 behavior; done means identifying a reproducible cause or a confirmed supported flashing path.

Written by the indexing model from the issue text.