ok you say you have an 11.6 3DS. might want to hold on updating it, dont want to burst your bubble but there was the 4 exploits Smealum released at the time of Defcon, they're not useful *YET*, anyone can care to correct me if im wrong but it's from what i *Think* a primary entrypoint (which would lead to CFW rather than just Usermode,) be it for free or not i dont know. ( i honestly dont care at almost 12:30AM my time to search) so your sitting on a potential way to lead you into CFW,
your R4i SDHC doesnt seem on the compatible list neither, for your question about the whitelist and blacklist, for a long point Nintendo was trying to combat DS-Piracy with known cards, and they did so by adding each card to the blacklist and cart devs got around it w/ newer exploitable Rom headers. some couldnt be updated, some could be update dfor the reason of no flash Space left for it's bootloader (only reason AceKard2i didnt see continued support, no more room.) they have every right to combat piracy as they see fit. unauthorized devices for any platform are a 100% investment Risk. and any update can break your Addon, cart , cheat disc etc and your w/o a single legal right to complain.
at this rate? well, all thats left if smealum's exploit chain when finished into something usable by the end-user isnt a free method, your only option is to hope finding someone willing to help you & pay shipping to n fro. (since your hellbent on not paying a single red cent.) and the more you complain, the more you avoid having to pay the more you whine "Why should i haveto PAY for cfw!?!?" the less and less likely someone's going to go that far to help you. and your likely to be banned if you keep up the complaining if you think "If i get loud enough and complain alot someone will finally help me to shut me up!" before someone breaks down.
not trying to be a dick but stating the facts, your atm in a highly questionable position for a free CFW method. and for "No Nintendo point cards in Europe" thats a falsehood, i've known quite a few spanning thru the UK that can get cards, Maybe none of your Local stores sell them. ohh and even if your flashcart was compatible you'd still need to buy a usable magnet if you dont have on.
your last resort is going to be having to sell BOTH 3DS's and try to get an exploitable one. or atleast something that you can afford to give up to get a usable cart for ntrboot.