In the Roval instructions, I don't buy the statement that you can't use a tensiometer because of the elasticity of their nylon bushing/washers, although it is necessary to figure out and estimate how the seemingly unique spoke blade dimensions affect the tensiometer's number reading.

There's no way that the washer's elasticity matches or even approaches that of the spokes, or these wheels would be floppy, and they aren't.

I used a tension around 80kgf I'd guess, since I had no tensiometer.

And as far as equalizing spoke tension on either side of the wheel, one can pluck spokes to compare tensions of adjacent spokes to a high degree of precision, within 5% easily I'd say.