What if people contribute to my fundraiser but not enough for me to reach my goal? If you have enough to make up the difference just contribute your own funds to the fundraiser so that you do have enough. That's perfectly acceptable in my opinion and I hope it is clear to contributors that the recipient can contribute too. source

isn't it simpler if contributors provide the fundraiser with a signed TX without requiring a specific output amount? He can take the money in both cases, and he can abort the fundraising in both cases If contributors didn't commit to an amount then the recipient could take the money without reaching the goal. I wanted the fundraiser to require him to reach the goal, and that's what my software enforces. Some recipients can fulfill that requirement by simply making up the difference using money they already have (and I encourage them to do that if they have the means), but in many fundraisers that won't work because they just don't have enough money to make up the difference. I think my way is therefore better