Nut upsuser - Jan 2023 - experience with old Best Fortress? shutdown not seeming delayed

I have several Best "Fortress LI660", manufactured ~1995, which use
bestfortress(8).  nut has been monitoring two of them just fine for
years via a USB/serial adaptor and homemade TXD/RXD/COMMON cable.

I am now trying to properly set up LB shutdown and have a few questions.

1) ups.shutdown.delay is set in the driver:

        dstate_setinfo("ups.delay.shutdown", "10");     /*
write only */

It seems nut in general documents 20, but I can't find that.  10 feels
short as a default.

The "write only" is confusing.  There is no way to set this, and
it's
read when shutting down and is available to read in general.

Should this be changed to 20, and the comment cleaned up to say that the
user can't change this?   Why shouldn't it be changeable?

2) At shutdown, that value is used to generate a string which should, by
code reading, look like "OFF10".

I have the dim impression that there should be a space, as in "OFF 10"
but I could have bad memory or be confused.

3) It seems that "upsdrvctl shutdown" leads to rather immediate power
off, not a 10s delay.   Power to the load stayed off and came back.
This is with 'upsmon -c fsd'.

4) The driver says

        grace = dstate_getinfo("ups.delay.shutdown");

        if (!grace)
                grace = "1"; /* apparently, OFF0 does not work */

and I wonder what happens with OFF0.  (Clearly OFF%S dereferencing a
null pointer is bad.)

5) It looks like an incomplete conversion to upslogx, and some remaining
printfs, obviously to be fixed by someone with time and interest.
Correct?



It's now on my todo list to see what happens with these commands; I
have a spare chassis w/o batteries that I can test with.