ProPresenter by Renewed Vision is an excellent app, and they provide an extensively capable remote control app, but that app gives users too much control. Making use of the new 7.9+ API, this app intentionally limits what can be done and it also provides facilities for the main ProPresenter operator to enable and disable the app at will.
With this app, pastors and other presenters will be able to control their slides and only their slides, and ProPresenter operators will be able to send them messages as well.