I am able to update the TinyTV software using a Mac (M2 Mac Mini running MacOS Tahoe 26.6.2) but there are some undocumented limitations.
1) If you use a VPN it must be turned off or disconnected. The update process is not compatible Proton VPN.
2) The update process is not compatible with all browsers. It does not work with Firefox but it does work Google Chrome  .
3) I used a USB-C connection via a powered hub connected to the Mac Mini's USB-4 port.
4) You have to use the manual process (that involves using the reset button on the bottom of the TinyTV.

Hope this helps someone