Velocirapture

I hope you guys can give me more guidance than google has so far.

I'm about to buy a very lovely frame, that the manufacturer notes as having a english threaded 68 BB, and a 53.5 chainline (which seems a bit wide to me?)

My current Pro-Lite Sardinia crankset will be built across - and the specs for this are BB:108mm JIS taper, with a 44mm chainline.

Am i correct in undersatndint that 108mm is the recommended length of the spindle? (i have now discovered that square taper comes in many spindle lengths!)

if 108 is not the recommended spindle length, would anyone be able to point me towards what would be.

Additionally, is there some way to correct for the stated 44mm to 53.5mm, as almost 10mm is a big difference. (unless i am misunderstanding the frame info).

Any imput on interpretting these numbers will be appreciated! i'm buying the frame and BB online, so wont be able to get input on the shop floor, so to speak.

thanks