That is not recommended for Zigbee2MQTT as they still listed it as experimental because Zigbee2MQTT does not yet support Zigbee network backup (adapter NVRAM backups) from Silicon Labs based Zigbee Coordinator adapters. More detailed information on that here → [WIP]: EFR32 EZSP adapter implementation and test · Issue #319 · Koenkk/zigbee-herdsman · GitHub (which will change listing recommendations only if and when Zigbee network backups are fully supported for Silabs ezsp adapter → Supported Adapters | Zigbee2MQTT )
My advice for a “production enviroment with full Zigbee Coordinator / Zigbee network backup” would therefore be to instead buy a new “Sonoff ZBDongle-P” (a.k.a. “Dongle-P” based on Texas Instruments CC2652P) and do a new parallel installation of Zigbee2MQTT to allow you to reset and migrate one device at a time.
Then later after the migration is complete you can convert your “Sonoff ZBDongle-E” (a.k.a. “Dongle-E” based on Silicon Labs EFR32MG21) into a dedicated always-on Zigbee repater/extender by flashing it with Zigbee Router device firmware and powering it with a USB-changer. Preferably even start by buying a few additional of those and convert to dedicated always-on Zigbee Router devices so you can begin by adding those before migrating any devices, as then those will create a kind of backbone network nodes that will make your Zigbee network more stable overall.
Regardless,I highly recommend that you read this guide before getting started and try to follow it if possible → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage
Summary; the more “known good” Zigbee Router devices you have that are always connected the more stable your Zigbee network will be, and having a few “known great” Zigbee Router devices will usually give a much better Zigbee experience overall.
Suggest also reading this → Not many people know that... A random collection of Zigbee trivia
A suggestion if you want to help the ZHA community a little then consider at least pairing/joining it to the ZHA integration while you still have it and submitting a device feature request with device signature + ZHA diagnostics in an issue to the ZHA Device Handlers (a.k.a. ZHA-quirks) project repository → https://www.home-assistant.io/integrations/zha#how-to-add-support-for-new-and-unsupported-devices
If you want to give back it simple job for you that will help others in the future who buy the same device.