CPROBJ questions

Being asked to recover every last bit of DASD possible from one of our
client systems while we await additional DASD.  From what I've seen, they've
covered just about everything I can think of except for compressing objects.
So please answer only in response to CPROBJ issues.

The question concerns the following statement in the CL Programming manual:
"The program must not be running in the system when it is compressed, or the
program will end abnormally."

If I specify the DAYS parameter to select only those objects that have not
been used in the past nn days, would I really have to worry about ending any
programs abnormally?  I would think that the "Date Last Used" for an object
would be updated as soon as it is called upon.

Also, does anyone recall whether there is a benefit to first using CPROBJ
OBJTYPE(*PGM) PGMOPT(*OBS), then using CPROBJ OBJTYPE(*PGM) PGMOPT(*ALL)?
As opposed to only doing the latter?  The idea I seem to recall is to keep
the observability tables compressed even if the program object is
decompressed.  Yay or nay?

TIA,
- Dan Bale