AFAIK, there are no LE Birmingham inks, though who knows if some might be discontinued at some point. I've come to kinda hate LE anything, but especially inks and notebooks. Anything where I feel like I'm being marketed to. 'course I'm always being sold things, but some subtlety is appreciated.
Pens only bother me when the edition is so small you can't get in on it like Retro 51, the Pelikan M200 colors where you can still get some years later are OK.
As for the Birmingham ink colors, how he's going to add 5 colors a month to an initial 40 (I forget exactly, but that's what's in the $50 sample set) and keep it all in stock I have no idea. The bottles are hand filled so if it's like my old printer cartridge refilling job, there are 5 gallon containers with pour spouts in the warehouse. Maybe 50 colors on a set of shelves? The supplier I guess can make them up as needed, I assume. IDK.
In any case, I appreciate the Diamine-like wide range of colors for $8 ea ($6 in the subscription), vs other popular inks these days north of $17 (Oster) or $36 (Bungbox/Edelstein/Colorverse/CdA/FaberC). The Birmingham line is made in Germany, so it's different from the Chesterfield (by Diamine0 that they used to carry when it was X FountainPens. I have to wonder if the German maker is the company behind Seitz Kreuznach's pretty wide range of in-house ink. Wouldn't mind if it was, as those seem to be really good, if rarely spoken about.
I enjoyed getting the new Diamine releases back when they were doing them, so this is kinda the same fun. I also joined Pipsticks subscription service to add some stickers as well as ink colors to my letters.