interesting read and cant understand why i missed this thread in the past.
As you know I have an Electrexworld race alternator fitted to my Croz replica. My experiences of them match yours. They are happy to take your money but follow up customer service is appalling. I also had a number of issues in terms of fit and performance which I've had to deal with as they are simply not interested. (Rob - zed1015 i did message you recently....). Last issue as you know was the oil seal that let go at Donington dumping oil on the back tyre with the resulting physical and financial pain.
I was thinking of fitting one of these to my Lawson but probably wont bother now as they dont seem to have got their act together and still use customers as a test and development process.
Z1000R, Moto Martin GPz, z900 A4 Crosby Replica, Harris Magnum 2, Suzuki GSXR 1100 Slabbie, SP1 Hoonda, Katana 1100, Bimota SB6R and Tuatara, Ducati 999