At this point, "letters space" and "third space" both refresh the FIGS/LTRS
toggle and the SI/SO toggle.

But what about the UC/LC toggle?

This could be regarded as less critical, of course, since if it is scrambled,
messages wouldn't be turned into gibberish quite as badly.

But since there is one position left in the figures shift, perhaps something
could be done.

One possibility would be to change the "figures space" character to "lower
figures space", and use figs-B, the unused position, as "upper figures
space".

However, it isn't that often that figures space would be used in normal text,
since it's a space in figures shift, so it would be a space between one group
of digits or punctuation marks and another.

So another possibility that seems to work well for the most common case might be this:

Leave figs-J as "figures space" which prints a space without leaving figures
shift, affecting no other shifts.

Make figs-B "upper letters space", which prints a space, goes to UC shift,
and goes to LTRS shift, without affecting the SI/SO toggle, unlike both
"letters space", which sets SO, and "third space", which sets SI.

And have both letters space and third space set LC shift.

In this way, after going to figures shift to print a period, one could exit
figures shift with an upper letters space to start a new sentence... and
after going to figures shift to print a comma, one exits figures shift with a
normal letters space (or a normal third space, if in the alternate alphabet)
so that the next word is in lower case.

John Savard