Even if Efke was being discontinued (in God we trust, but the rest of you should bring evidence!) still got
Rollei IR to fall back on.
To assimilate yourself with near-IR experience, get some
Ilford SFX film in a smaller format e.g. 35mm or 120 so you can bracket up and down. Doing so is wasteful in 4x5. It's not true IR film but it comes very close to the effect (and is easier to work with to boot!) with an
R72 filter (el cheapos from Hong Kong do the trick; no need for Hoya's $300-gigadollar dazzler) and that's good enough for experimenting with before investing in the more precious stuff. It's best on sunny days with scattered clouds. Not sure what the #87 filter is for.
I have three rolls of Efke AURA in deep freeze. But experimentation is taking place with SFX 200.My working formula for that is set ISO to 25; meter scene with IR filter
off (either camera meter or handheld); bracket 1 stop up and down. There will be duds, but you should get a couple of good ones on the proviso conditions are suitable for "near-IR" imaging, as noted above, bright sunny sky and some clouds and a strong composition e.g. a barn in a field, windmill, old car, ruins... whatever you can find.
No doubt others here, when they stop talking about who is discontinuing what and when and start getting out there, will have their own experiences about exposing IR/pseudo-IR films. It's an interesting type of photography.