Its really shouldn't matter if you are sure that the project is real and the idea is not bad, i have seen whereby people leave a bounty for another bounty and they later regret, its like throwing away a diamond and running after stones
It does not but delays do create a space of doubt in the hearts of participants. If suddenly time extends, people would like to know the reason behind such actions. I will not suggest him to leave the program as it will waste his previous efforts too but he should join some other potential bounty simultaneously. This will save him from risking anymore time. He should also look for ways other than bounty.