The capacitors in the mag filters are there to form a resonant spark
(electrical) tank circuit with the inductance of the magneto coils and
protect the ma=gneto points. If you hang additional capacitors on the
P leads, the mag functions will get completely screwed up as the
resonant frequency of the spark tank system will be depressed - if they
even work at all.

I should have mentioned that the three controls I noted are accessible
thru the top cover of the radio once it is removed. Mess with it
gradually and carefully.

The ICom radio is very sensitive. Even with my squelch setting
modified I'm still picking up transmissions from over 125 miles away.
I wish the squelch was more user real time accessible.