I also have a T-Mobile 4G LTE biz account at home, using a four antenna Ethernet/WiFi router - it has a SIM card slot. It's been very reliable for years, though have seen an occasional drop-out since T-Mobile pushed out a network enhancement a few months ago. May have had something to do with 5G upgrades?
Upload speeds have also been somewhat erratic lately which is of some concern as I work remotely for now. I got grandfathered into this account, paying $79. month w/250G 4G data/month. It's now $249. month w/200G 4G.
Ironically, I've found Verizon Visible service faster with no 4G LTE data caps, and less expensive at $40. month? I use it for travel, and as a backup to T-Mobile to offer some insurance that I can continue teleworking should there be an outage on one network.