Welcome to the wonderful world of Victron. I keep finding "interesting" things all the time.
I have a MultiPlus II + Cerbo & Touch 50 display + SmartShunt + VE.Bus Smart dongle and now the VE.Bus to USB dongle.
Pretty sure I didn't need all of these. Anyway . . .
The Touch 50 display & VE.Bus Smart dongle "interfere" with each other. I don't remember which, but one prevents some info displaying on the other.
VE.Bus to USB dongle is essential. It allows setting parameters that the other dongle & display can't.
However, the VE.Bus to USB dongle only appears to work with a standard Windows PC. But I have a Mac. Luckily, I can install Windows on my Mac so I think that should work. I'll find out in a few days when I drive my RV up to my house window near my computer and run 25' of ethernet cord from Computer -> VE.Bus-USB dongle -> MultiPlus inverter VE.Bus. Lovely.
Finally, the advice I've been getting from the Victron support web site has been problematic -- some folks there don't know what they're talking about, and I'm too new to tell the diff. Luckily, Chad has been around here.
Finally, finally, the cherry on top was discovering that I can only use 1/2 my generator's power with the MultiPlus (see Combining L1 and L2 ...) unless I modify my gen's output.
Finally, finally, finally, despite the gotchas, I think (hope) these are growing pains. When I start wishing that I had installed a Magnum inverter instead, I think about the two Magnum MS2000s that failed me.