Ok, with a bit of Gemini’s help I think I have an answer. There is a field that can be added to the .ics file that the webcal link points to which will (hopefully) achieve it.
Gemini’s take on it:
To add a name to a Google Calendar subscription link, you cannot use a direct URL parameter like
&name=. Instead, Google automatically pulls the name from the source file or requires the user to rename it manually after subscribing.If you are the developer or creator of the
.icsfile being linked, you can set the name that appears when someone subscribes by including theX-WR-CALNAMEproperty in the file header:BEGIN:VCALENDAR VERSION:2.0 X-WR-CALNAME:Your Custom Calendar Name ... END:VCALENDAR