[-] Upgrades do not extend delivery time from the UM

[Tha_Ape]

I just bought a used 757PF from the UM and requested winglets to be installed. Delivery time remained unchanged, at 2 weeks.

All other maintenance tasks performed upon purchase usually lengthen the delivery, even if sometimes partially integrated.
3 weeks instead of 2 would seem in line with the other options in this case, 4 weeks would be a little long.

Or is it a deliberate choice?

[Sami]

Yes it was deliberately left at standard 2 weeks.