You *may* have misunderstood the "+4" thing. +4dBu is still a commonly used physical interconnect - it's what's used on line-level XLR connectors.

A level of +4dBu equals 0dBVU, but analog gear could often go much higher. It's been a while - my numbers may be a bit off - but a mixing desk output might be able to hit, say, 15dBVU, or is it 15dBu. A tape deck would start to saturate at a few dBVU, but could be pushed quite a bit higher.

I'm not aware if there's a standard for "digital" meters. Maybe it is the "0dBVU = -4dBFS" that you've used - I dunno. In digital, it makes a lot more sense to me to simply use meters that make 0dB the max!