Just so that people who don't fly the B737 understand, once you have localizer and glide slope capture in Approach mode, you can't simply select a different pitch or roll mode.
From the B737-400 Operations Manual:
After VOR/LOC and G/S are both captured, the APP mode can be exited by:
• pressing a TO/GA switch
• disengaging A/P and turning off both F/D switches
• retuning a VHF NAV receiver.
gas chamber, I suppose there is nothing wrong with that except to say that it doesn't sound like you could increase the workload even if you wanted to.
Make that co-pilot work!
Sounds like you wanted to!