Is it usefull that if the project is with 100% fundet, people could still fund this project over 100% and the project waits the whole time until it defind end, or would it be better, if the project is 100% funded, that its over and there is a imitiat paypout?
perhaps there could be both cases available when a cf project ist startet?
It comes down to whether you want to minimise the fees as much as possible (which is why it works as it does now).
Currently it uses a clever "trick" to work super-efficiently by avoiding executing the machine code until the target block is reached (so although the % gets larger and larger no actual code is being executed while that is happening so it is tracking that progress "for free").
If we did change the behaviour (which of course could be done) then understand that it would cost everyone pledging or donating that little bit more (and waste more clock cycles for each node to verify the AT). This is due to a "min-fee" that is needed to cover any steps that are executed at each new block height.
I'm not sure if the button changes from Pledge to Donate automatically at 100% but if not that of course should be changed (luckily as that has nothing to do with the actual machine code that can be changed by updating the UI for that AT).