If you are printing using the Adobe print driver below, you will not be able to set this as a default, however if you are using the Xerox print driver, the settings can be set as a default. Click the link, to view instructions on how to set the printer defaults, https://www.support.xerox.com/en-us/article/en/x_alb80xx_en-O3363.
Which print driver are you making the setting changes on?
Adobe
Xerox
User CAN set scaling to fit on per-print basis, but CANNOT set scaling to fit as the printing default.