I've owned several Ricks and have often experimented with Rick-O-Sound. For me it's the only way to get "that" tone I grew up chasing - Hemispheres, Close To The Edge. You can certainly get close to it running mono, and there are a lot of pedals and devices available these days to get close to it - the Tech 21 Dug in particular. That said there is nothing quite like running a Rick in stereo at volume.
You don't necessarily have to use a guitar amp either - in fact a lot of people on YouTube showing of Rick-O-Sound seem to miss the point somewhat, running the neck pickup through a bass amp and the bridge pickup through a small guitar amp, ramping up the distortion and getting a strange disconnected sound that doesn't sound good to my ears at all.
In a way it's the deficiencies of the instrument that make Rick-O-Sound necessary - the top end and growl of the bridge pickup is unbeatable but it struggles in the low end* so running the neck pickup separately gives you the big lows back. I adore Rickenbackers but acknowledge they do have plenty of foibles you have to deal with 😄
The real RIC splitter boxes are ridiculously overpriced. If you're handy with wires and a soldering iron it wouldn't be hard to cobble together a splitter box but if not Raygun FX can knock one together for not a lot of money.
Bottom line - if you're getting a Rick there's no reason at all not to give it a go! I'm surprised to see such strong negative reactions to the idea, that's something more common on Talkbass.
* The current 4003 uses overwound pickups so they're a lot hotter and fatter but lose detail on top.