Routing static line

I am looking to route a 1/4" static tube from behind the baggage bulkhead along the side to the instrument panel to add a standby altimeter. There are already two holes through the bulkheads, one under the armrest and one under the top longeron, along the sides with the pitot line and network wiring back to the ADHARS.
I am wondering am I better to enlarge one of the existing holes to accommodate the extra tubing, inserting a larger grommet, or is it better to drill another hole just big enough for the new tubing and grommet below an existing hole. I believe the best place to drill any holes in a structural member such as these is mid point between the edges, is my thinking correct.
I have searched past posts but most seem to develop into other discussions before a definite answer is revealed.
Any help would be appreciated. I have looked in the assembly manual and plans but cant find any direction there.

How to run the static line

Typically the static line to the panel will pass through the cockpit area just beneath the top longeron (rather than under the armrest, although some might). There should be enough space at the top of F604 to feed through 1/4" tubing without drilling any holes there. For the next bulkhead aft, Vans suggest to drill a 1/4" hole for the tubing near the top of F605. No grommet is required. Note F604 is very structural (in a crash) and should be left alone if you can.
Assuming that your existing pitot and electrical wiring are on the left side, you can run the static line on the RHS of the fuselage and tee it into the static system tubing that connects the two side ports behind the baggage bulkhead.

Thanks Paul I will look a bit closer tomorrow. I do want to try to get the line down the left hand side as well to keep the length of the tube as short as possible and it would tap into the static line easily.