Worn out BK flip-key

Hi everyone. I'm scouring ebay for flip-key replacement housings as my BK's keys have gotten flakey; key blade is loose - in fact one of them the blade seperated from flip piece - and they are basically worn out.
The replacement process is documented in the youtube clip below. The main hurdles for a pain free key replacement is the transponder chip being glued in and the fact that apparently most of these clone key fobs aren't 100% identical to the mazda units. If they were you could transfer the blade and transponder chip to the replacement housing with little effort.

I'm wondering if anyone is aware of a unit that is sufficiently identical to the mazda unit that the actual key blade fits without needing to cut the blank (swap blade over)? Is anyone aware of units with transponder chips that can be coded to the vehicle? Those described in the video, which I am assuming applies to nearly all ebay blanks do not include a transponder. Consequently the glued-in transponder chip must be carefully cut out of the old housing and transferred to the new one.

I have seen standalone transponder chips available through ebay. Has anyone used them alongside blanks like these?

I think I will also get a third simple key without remote entry and document the process of rejuvenating my key set.

Mazda quoted like $500 for replacement key so looking to do it myself. Locksmiths I've asked aren't much help either - they'll happily cut a blank you give them, but ask them what you should do and you get pointed at the $500 option. Last one who answered that I was tempted to ask "you're a locksmith aren't you?"

Any experience anyone has to share would be appreciated.

https://www.youtube.com/watch?v=sA2cQnN4VGU

How did you end going with this? Needing to get mine replaced and a spare made up

I haven't pulled the trigger on this yet, but one option you might look into that I hadn't thought of until I saw another FB discussion on this was to find some OEM BK keys from a wrecker to transfer the internals (blade, remote, and transceiver chip to).....it's simpler than the replica keys available on ebay because the blade and retaining pin fits perfectly, whereas the replicas don't.

I am intending to try to program some spare (additional) ignition keys and I'll document it when I do