So due to the installation of fiber being delayed we are running a new site on 4G for a few weeks now. We have real world experience now. Thought it might be worth sharing.
There was a weird disconnect happening every day. It seemed to be after a rolling window of 24 hours. The provider we use, Odido (formerly T-Mobile Netherlands), doesn't allow 4G sessions longer than 24 hours. So we just set-up the modem to reconnect every night at 3AM. That way we have control over it.
With an
outdoor 'puck' antenna and a cheap TP-Link modem MicroMPX over WireGuard seems to be pretty stable. Besides the nightly connection drop we don't see much drops. Recovery packages are being used a couple of times per day but that doesn't cause dropouts. The latency of the connection sometimes goes from 40msec to 80msec but MicroMPX seems to be able to handle that. No packets too late.
This is the Smokeping graph for the site. Confirming it's stability. MicroMPX doesn't seem to be fundamentally incompatible with 4G or WireGuard.
If you're experiencing problems it might be worth putting Smokeping on an intensive monitoring scheme for the link itself.