What innovative, unconventional cartridge designs can you recommend?

So FSE is an acronym that means roughly the same as FOS?

I daresay there are other three letter acronyms that might be suggested! Although, I am of the opinion that a longer abbreviation might be what is required here: LiCO₃.

@pindac 

There's no reason you should have to pay a tariff on your own cartridge making a round trip out of country, as long as all appropriate paperwork was filled correctly. This is a common situation.

I hope I'm right, because it looks like I'm about to embark in the same situation myself :)

Apologies for ranging off-topic.

The much wanted Service pulled the Plug on dealing with the UK, things got very messy at Brexit. 

Pre Brexit purchases were arriving at peoples doors with demands for near £100 fees to have the goods made available. Loads of purchases were left with the Postal Services. It is also from recollection, an occurrence that when the EU Vendor could be contacted, the same requests for monies was being sent. Carpet Baggers and unscrupulous services rode the confusion until their intentions were seen as futile. Hence mainland EU retracted from dealing with sending items to the UK that was typical to them prior to Brexit.

For the UK to export living animals, the Paper Trail to be produced for each export, was not achievable in a sensible time line. The activity was more than bordering on cruelty, as animals were contained in transport vehicles for substantially increased period than ever known.

Northern Irish Businesses that exported Elvers to mainland Europe in the Millions went Bankrupt very quickly, as each young Eel needed individual Paperwork and proven traceability.

Anybody who travelled regular in the EU, especially those with second homes, or long term deals done for accommodation, who could qualify through Hereditary for a non British Passport, acquired Passports for EU and non EU Countries, as traveling in mainland EU was to much freer than being British. This methodology spread like wildfire for multiples of UK residents wanting to got to the remaining  EU.

My own EU Properties are not visited for multiple years, which is a sad case to be attached to. 

I made some anagrams of the names of a couple of our most verbose posters, but thought it would probably be deleted.

Some decades ago on usenet there was a mantra: post quality, not quantity.