I can say that I am a bounty veteran, started my journey in the first bounty ever on Bitcointalkand am still here so I can easily say that I have seen and did everything when it comes to bounty and rewards.
From my experience, it seems that the best strategy for any rewards is the 50/50 rule, which means, that you hold 50% long-term and sell 50% at the best price just after payment.
In the early days, some bounty rewards were good to sell at the start and some little later so this strategy works best anyway and is easy to follow.