Great setup! And directions are very clear.
I had never noticed the SS TFA1s before, a handy problem solver.
Just a note to viewers, eye relief will need to be on the long side.
I ordered my early 1980s University Optics Comet King 20x80 binos with the nebula filter option, a thick filter bonded to a copper plate that, IIRC, went underneath the rubber eye shield (an alternative method that might work with the SS TFA1s!).
With the short ER oculars it was barely usable and, also in part to my B9+ LP and the filter's overall transmission reduction, they were used only a few times despite the cost.
But it was a great idea, just ill-applied.
Your setup looks great and should do well with most of the eyeglass friendly long ER oculars made today.
I also don't know why this is not built in on long ER Astro binos (for non-eyeglasse users).
If the filter body height does not work for a reader due to short ER, it might be possible to bond the filter element to the SS adapter, presumably just within the adapter opening, if recall filter body dimensions correctly. Or even to a thin, wide flange washer is an appropriately sized one is found.
That would be similar to the UO version, and likely work a bit better as they chose unusually thick double layer glass filters at that early date.
This would also let you use the coated Baader Moon and Skyglow filters, the only filter I found effective in B9+ skies, at least until they install the hated LED street lights. Nice neutral views with minimal reduction of overall light, they should do nicely with the limited bino apertures.