[LAD] Plugin 1/oct frequency controls (AMS/MCP/VCO)

Hi all, I am porting to LV2 some AMS-influenced plugins (mainly those by Fons) which have odd 1/Oct frequency ports. I understand why it is sometimes convenient to use octaves rather than the more typical Hz for frequency, but after some digging to figure out how to precisely describe this unit, I discovered the central frequency is middle C, i.e. C4, i.e. around 262Hz. For hosts to be able to use such plugins effectively, I need to precisely describe this unit (and then other plugins can implement to spec and they will all get along). We already have an 'octaves' unit, but no base frequency is defined. I can add one, but I am not sure about this strange choice. Nobody tunes anything based on middle C, with its odd frequency of 261.62556... writing this in a spec gives me pause. I suspect it evolved from MIDI code in AMS where the 60 of middle C looks as reasonable as anything else, but when you try to actually define/document the unit it looks silly. I think the natural central frequency to use is A440, at precisely a nice round 440.0 Hz, so 0.0 is A4=440.0Hz, 1.0 is A5=880.0Hz, -1.0 is A3=220Hz, and so on. Whenever a default or center or tuning frequency is needed, you use A4/440Hz... tl;dr: I think the most reasonable standard for an absolute 1/oct frequency unit is 0.0 = 440Hz Thoughts? -dr