I know Aviation Megatore have some exclusive European & Worldwide distribution rights regarding some lines they do (the SAAF conversion sets & Decals for one) so they are likley to have an exclusive agreement with UPS for global parcel distribution. Delivery constraints and costings are an issue with UPS which gives them a global reach even if not the best for pricing.
Its only really a problem if you or your other half are both away form home for a few days as if they can't delivery it person that day they will leave a card so you can arrange a redelivery or collect from Depot with the local UPS office. However if your not in and don't have anybody checking the post then they will likley try 3 times and then return the parcel back to source

. If you are home and miss the delivery then you can contact the UPS depot and come to a more practical arrangement at a local level rather than trying to deal with the initial rigid systems.
Alternately arrange to have it sent to a location you can rely on, parents, LMS if you have a good relationship with them and collect when you can.