I also tested with my phone's 5G and got about 100. If their office boss won't stump up for a 5G sim modem at least the 4G will give them a consistent connection.

SKYBOXE®, the new 5G company that's on a mission to "unwire" American households, today offered a first glimpse at the effortless setup experience behind its upcoming SKYBOXE 5G Fixed Wireless Access ...

If I understand correctly, you want to plug the USB-C network adapter directly into your phone, then plug the other end of the network cable into your router.