🚀 go-pugleaf

We have gotten several requests for support of international
character sets, and for "8 bit clean" troff. We need some
help figuring out what is needed.  Ignoring for the moment
Kanji as a separate case, this inquiry is directed to the
European market.
If we select a specific character, say the Swedish character
that looks like an a with a circle over it, as in the second
character of my ancestral home town, Bastad, then the following
implementations are possible:
1. Using the current DWB troff longname convention, you can
address any PostScript character, viz. "B\N'aring'stad"
(aring is the Adobe PostScript name for this character, which,
for the non-Swedes, in pronounced "oh").
2. We could invent a new troff escape, viz. "B\(aostad".
We don't want to invent one if there is an established convention.
3. There are apparently 8 bit internal representations that
are created by double striking keys (perhaps ESCAPE A, but I
don't know). I need to know if there is a practical standard
for such (i.e., one people actually use).
4. I recall some countries (e.g., Scandinavian) use ordinary 7 bit
punctuation chars in lieu of these letters, viz. "B{stad"
or somesuch.

I don't want to hear about every pending international standard.
I want to hear what people who will be using the software would
like to see.

If you have answers to the above, please send them to npn@mhuxo.att.com.
I am looking for data, not opinions, so replies from Europe
will be heavily weighted over others. I am not trying to
create another "gaol" vs. "jail" controversy.