The LED is perhaps the solution for VW/VV
Construction space should be perhaps smaller,
than for a screen.

Blue = minus 10 watts
Orange = minus 5 watts
Green = normal mod
Pink = plus 5 watts
........

Or by numbers: -2, -1, 0, +1, +2, +3 on the LED,
steps in watts or volts.

Fixed voltage would result in a very very small tube like the Atto.
VW/VV would need some mm more:

The Atto is 79.
With more electronics perhaps 84.
And this without bottom on/off 81 to 82.