personally, I think questions like this may get better response if posted in the "ask all sailors" section, because cockpit drains and the issues with them draining slow isnt specific to the boat you own, but is problematic on many brands of boats when there is a large dose of water ingested into the cockpit on a regular basis...
there are 4 drains in the cockpit of our 34 (one in each corner), which is better than two ONLY IF the water can get out the thru hull fittings/valves as fast as the scupper holes can take it in, of which there are usually only two thru hulls draining the 4 cockpit scuppers.... the entire plumbing and its routing DOES matter.
but really, I think 4 cockpit scuppers a lame effort to drain a lot of water out in a hurry.
if it were me trying to figure out how to dump water from the cockpit faster than (2) 1-1/2 " drains could allow, I would install a large 3" or 4" thru-hull fitting in the rear wall of the cockpit footwell, and then use a stainless transom exhaust outlet thru the transom..... with a rubber hose connecting them together, and use a rubber exhaust flapper on the outside, if necessary to keep a surge out.
one 3" tube will allow twice as much water flow as (2) 1-1/2" tubes will, and a single 4" tube will allow 30% more than that.... and a single large drain is much easier to install and plumb...
the installation of a thru-hull in the in the rear of the foot well wall will probably be high enough so there would be no back feeding due to wave surge, but the flapper valve would insure this, if necessary.
and it does not need to be at the very, very bottom of the foot well, but as low as possible would be reasonable because once the majority of the unsafe weight/water drained away, the last couple inches will quickly drain away thru the smaller existing scupper holes....
