SVO=MVO=Tr for U+3030 (WAVY DASH) will be good when most CJK fonts have the 'vert' glyph for U+3030, but unfortunately major fonts such as Hiragino and Kozuka don't have the 'vert' for U+3030.
That's no problem if the 'Tr' means Rotate if cannot Transform, but in CSS3 Writing Modes §5.1.1. Vertical Orientations
the VO value 'Tr' is treated same as 'Tu' (“... If the orientation value is ‘U’, ‘T’, ‘Tu’, or ‘Tr’ then the simple value is ‘U’.”) and the WAVY DASH will be set Upright if cannot vert Transform. I think SVO=MVO=R will be better in this unfortunate situation.