In-Panel 396/496 Setups with the 430/530?

Does anyone have this setup where the 396/496 (particularly the 496) is
in their panel hooked up through an RS232 cable to a 430 or 530? I saw
a post by Mikem with very good specifics on the pin-outs but I have a
couple of questions:

1) Does the 496 pick up the inputted flight plan/route from the
430/530?
2) If yes, what's the procedure? Does it act like another IFR box where
you need to use the cross-fill function or is it automatically filled?
3) Again, if yes, how critical is it to keep the 496 up to date with
the same database? Will it behave badly if it is not in sync and there
is a renamed fix in the active plan? I plan on updating the 496 only
once or twice per year while I have the 430 on the IFR-mandated 28-day
cycle (OK guys, don't get hung up on the term "mandated"--you know what
I mean).

One last question, has anyone done the panel mounting of the 396/496
themselves or is everyone going to an avionics shop? I may need to
travel a bit to do this since the nearest [reasonably-priced] avionics
shops are in Connecticut and the word that their local FSDO is very
strict and does not approve of the Airgizmos installation on certified
aircraft. The local FSDO at my location (Farmingdale) is OK with it and
looks at it as an installation that does not require a 337 (although
recommended). However, I will want to do the RS232 conx so doing it
myself is out of the question.

Marco