If an athlete does not get special compensation for making the Olympic team in TWO events, then his/her agent should be replaced. It is not easy to be the best in the country at one event, let alone two. That's quite special and is often reserved for those who can compete at the international level as opposed to being an "also ran" in an event. Lagat (2008) Galen Rupp (2012 and likely 2016), Shalane Flanagan (2008), Molly Huddle (likely 2016) - they are/were in a level above all other Americans and the contracts they have/had with their sponsors hopefully reflect such.
So to Brojos - I would hope that anyone being offered $20K NOT to double would turn that down because there is an even larger bonus waiting for them at the end to do the double.