Here’s an update, spent some time adjusting pickup height and now the balance across the strings is perfect, also the string width of just under 16mm at the bridge works really well for my aging fingers.
With regards to the neck, there does seem to be a lot of smoke and mirrors surrounding the “Signature” brand, all I can say is the quality of fretting is excellent, it’s withstood the pressure of coping with 5 strings for 4-5 years or so, without any issues, also it’s 21 frets with finger board overhang, which seems unusual given its supposed age. Whatever the origin the end result works perfectly for me.