Yes, but there's no point if they will only be a few people contesting, and also DiamondYT's PMDC - PocketMine Development Challenge, https://github.com/OfficialPMDC/website creating two contest that's same in the grand scale wont help me nor them
A plugin request contest is better. Otherwise, it should be a "challenge" instead of a "contest"; something like a 100-line plugin challenge (reformatted automatically under a certain code style), or even an AI contest (write an AI for skeletons and let them fight), etc. BTW, great plugins are rarely finished within a fortnight. Even PEMapModder's swansong HereAuth took him three weeks even though he was putting everything aside to finish the last piece of work.