Lack of time is the major obstacle to effective participation. This is particularly evident when a sizeable group discusses something: matters come up that have to be set aside.
A solution is to place them in a Fridge for the time being: issues raised + the name of the persons who bring them up are noted on a flip-over sheet. Later, when there is a suitable opportunity, time is devoted to emptying the fridge. For this, the method Common agenda can be used to advantage.
See also the application Peter & Paul and the alternatives