Would Rubylith masking film work or is there something more suited for photographic darkrooms?
It'll be almost the same as simply covering the LEDs with black gaffer tape. LEDs are narrow-wavelength devices. A blue led emits around 450-480nm, green usually around 525nm, yellow/amber is around 580-600nm and red usually around 620nm. The cutoff frequency of rubylith is somewhere around 600-620nm, which means that virtually all light of smaller wavelengths is blocked. This means that your green, blue and amber/yellow LEDs will simply not show anymore and you might as well block them off with something like gaffer's tape or tinfoil, cinefoil etc. Red LEDs you can mask with Rubylith, but it's generally not really necessary if you just print B&W VC in that room. Of course for film loading etc. the place needs to be entirely dark to begin with.
You have to keep in mind that a filter like Rubylith doesn't change the color of light. It just blocks certain colors. If the light source emits a color that's blocked by the filter, you simply see nothing.
I had the same challenge you have since my darkroom is basically a multi-purpose space; it's my home office, darkroom, hobby room etc. There's a computer with monitors and all kinds of equipment, a network switch with blinking lights etc. Some of the LEDs I've masked with tape, in other cases (e.g. a network switch) I've actually removed the series resistors from the LEDs inside the switch so that they cannot light up anymore (external masking wouldn't have been effective due to all the seams and holes in the housing). Some equipment like the split unit aircon I just don't run when I'm working in the dark. Computer monitors I just turn off (standby LEDs are masked with tape), same with the cordless mouse. So basically I've decided from a practical and case-by-case viewpoint how to darken each of the unwanted light sources. I've even gone so far on a keyboard I used previously to swap out the green LEDs for amber ones (since I also print color), but on my present keyboard I've not bothered and I just turn Num Lock off when going to 'dark mode'.