Nothing is impossible.

All companies have audited accounts. Of course, you cannot audit before the event is over, but as soon as the event is over it is possible to audit any event in relation to expenses that have to be justified with invoices.

Even last minute changes due to inflation or for any other reason it is possible to audit through the invoices this way there would be transparency on all projects and no one in the community will "doubt" due to not having enough feedback from the projects on the objectives and the that has been fulfilled.