V7R1 *SNGLVL vs *INHERIT

In the MTU for V7R1, pg 17 is a discussion of *SNGLVL vs *INHERIT as storage
models.

This reared it's head for me today as I'm trying to make a few changes to a
service program. I can create the *MODULE object with CRTSQLRPGI just fine,
but the subsequent UPDSRVPGM fails with this error:

Message ID . . . . . . : CPD5CD1 Severity . . . . . . . : 30
Message type . . . . . : Diagnostic
Date sent . . . . . . : 05/03/11 Time sent . . . . . . : 08:50:21

Message . . . . : Module storage model cannot be changed.
Cause . . . . . : Constituent module SUBBILL originally from library JEFF
cannot be replaced by module SUBBILL in library JEFF. Constituent module
SUBBILL is bound into SRVPGM SUBBILL in library JEFF and was created with
storage model *SNGLVL. The replacement module was created with storage
model *INHERIT. The storage model must be the same on the constituent and
replacement modules.
Recovery . . . : Replace the constituent module with another that has the
same storage model value, or re-create the SRVPGM.

This is what pg 17 in the MTU is referring to.

The MTU says (I think) that I can do a CHGSRVPGM(lib/pgm) STGMDL(*INHERIT)
TERASPACE(*YES) and be good to go. Is this right? My service programs are
a mixture, some with SQL and some not, and are all activation group *CALLER.
The calling programs are also a mixture of SQL and non-SQL.

Can I just do this CHGSRVPGM to all my service programs and all will be
well?

I need a smarter mind.