Ignoring the shameless extra fee grab suggested in your post, ….TASCAM is NOT alone in crazy backlogs for service, albeit they seem to stand alone with their queue jumping service requests.
I bought a high-end BRYSTON digital player and stablemate DAC pre-owned. I sent the player back to BRYSTON for a full software reinstall and general status look over . It went in on or about October 2021 and I got it back on or about March 2022, but only after I personally got ahold of the Service Manager. He got it back to me fully updated and shipped at their cost within 10: days after the calls, AND ….NO CHARGE as an unexpected but much-welcomed very classy gesture of inconvenience amelioration …. Ergo…. top-shelf service.
He did comment that COVID and supply chain disruptions both have played havoc in the entire audio industry. Available tech bodies were off sick because of COVID… etc. Supply chain parts shortages were - and continue to be - common.