Ha, yes, overthinking is a bit of a speciality of mine. Especially now with little else to do....
LAST question (I promise) - in the windows themselves, I don't like black spacers (I feel it just stands out and looks odd against white everything else). White or grey spacer both fine, nothing I'll ever notice anyway?
Snap, it can be a bit of a curse!
The question you're asking is completely subjective Assuming you mean the spacer between the glass panes, if the supplier offers different colours and you don't like the (default?) black, then yeah go with white or grey if you prefer. This gives an idea what white (maybe light grey) looks like:
Art Windows Services - Professional Windows & Doors Services across London