What you describe is possible only if you live close to a “point of entry”. I live on a Greek island. The point of entry is Athens. There is no way I can handle the customs procedure myself, as I have to get to Athens. So it is definitely much much better if L5 gets shipped from within EU. Customs must be avoided.
Now what if Purism does not find a way to do it. In that case I would ask @nicole.faerber to use USPS and not companies such as DHL (terrible service). USPS cooperates with all countries official post service and customs handling is free. You only pay the tax.
I once ordered a battery (it was a special form battery) from US. A 34 USD value. DHL called me from Athens and they told me I had to pay the tax plus 100 euros for handling the customs procedure. I was essentially forced to abandon the package.
So @nicole.faerber if you do not succeed in shipping L5 within EU, please at least use USPS.