After testing every option, the best current solution for a Roland U-220 VST is a hybrid workflow:
Does this sound identical to a hardware U-220? No. The hardware has a 16-bit DAC with a specific nonlinearity that software often misses. However, for 95% of mix situations, the SoundFont + sforzando combo gives you the velocity layers, the loops, and the character.
Since Roland won't make the VST, you have three options to get "The Box":
You might be thinking, "I have Omnisphere and Kontakt. Why would I want a VST version of a low-bit, low-polyphony rack unit?"
Three reasons: Texture, Limitation, and Nostalgia.
If you want this sound, do not buy a used U-220 on Reverb (the screens are dimming, the buttons are failing, and the internal battery will leak). Instead: