Xerox Phaser 7760GX and Phaser 5550DN

I have TWO Xerox laser printers (1) Phaser 7760GX (color) and (2) Phaser 5550DN (black only). These are both "workgroup" class printers with a variety of features supporting paper sizes up through tabloid (11 x 17). Xerox has NOT updated their driver since an update for Yosemite OSX 10.10. Their old driver causes many programs to crash -- and I am unable to specify many of the features of these printers. (Crashes occur with Preview, Mail, Text Edit (taught me to save before printing!), and other programs. Printers are connected to an Ethernet network.

Adobe Acrobat can control some features (that cause other programs to crash) but when trying to specify the MPT (or other specific tray) then it, too, crashes.

I contacted Xerox, and basically got a "too bad" response -- remarkably while the 7760GX has been superseded, the 5550DN is STILL A CURRENT PRODUCT -- yet no driver past Yosemite for Mac. (Both the 7760 and 5550 use the same driver.) Xerox indicated that the crashes occur because the driver "responds" to the application that is attempting to print (resulting in "unexpected" data and a crash). They suggested using the "HP Jet Direct" device through the parallel port on the printer. Does anyone have experience with this?

I tried a third party "Gutenburg" driver, but it was missing many features -- and now my Mac (running Mojave) notifies that the software is "incompatible" (probably 32 bit program).

I'd hate to get rid of these printers, as they were purchased for my book-design service (that was then hammered by the "great recession") so they're "low mileage" printers, with many years of future service life. I'd hate to toss 'em out due to the lack of a driver.

(I'm considering getting a used/refurbished Mac capable of running Yosemite to act as an intermediate "driver" platform.)

Anybody have any suggestions?