I feel you pain, I was in the same situation

However, I would not give up until end of May. (this was my original plan when I learned that I was being WL). Let them time to assess the quality of R3, and balance the class. The past showed that they make significant (i.e., more than 3 or 4 people at once) revisions of the waitlist unlit end of May. After, it seems that they don't review the WL so often. And you have to think about your own interest:classes begin the 27th of August, the big deposit has to be made at end of July, and with all the preparation you have to do (pre-reading, accomodation, visa, give up rent, give up job, etc.) I see it challenging to organize in less than 3 months.
Total number 434 today, with the breakdown for the more common nationalities (others nationalities have less than 10 people so over-representation is not an issue):
nationality tot M Famerican 53 32 21
indian 51 32 19
french 35 26 9
british 27 20 7
canadian 29 22 7
chinese 28 13 15
german 15 11 4
italian 18 15 3
lebanese 18 15 3
brazilian 17 12 5
australian 13 6 7
belgian 13 12 1
spanish 12 10 2
dutch 9 6 3
singaporean 10 5 5
Then, a little opportunity analysis. Let's say that they feel the girls are missing if they represent less than 25% for each nationality. Then the following nationalities DO NOT miss girls (and so, being a men should be neutral on your WL process):
american
indian
french
british
chinese
german
brazilian
australian
dutch
singaporean
japanese
russian
bulgarian
swiss
taiwanese
korean
turkish
ukrainian
greek
romanian
egyptian
iranian
swedish
vietnamese
chilean
thai
bosnian
emiri
finnish
indonesian
lithuanian
moldovian