Every now and then I will jump into a developed model and notice that users have created custom text types or keynote tags, Often times these text types and keynote tags will not be using the standard arrowhead type we use at our company.
There are several reasons this could happen,(copying details, to add something to the keynote tag, different text style, etc).
In Revit, the arrowhead style is a type parameter which is both a good and bad thing. If you have a very developed model with a bunch of different types, this could take what seems like forever.
Thankfully we have Dynamo to save us. See below for a video of the first Rhythm tool in action.
In the video I illustrate that all the text and keynotes are different types. Select the types to exclude (important if you need specific arrowhead types), and select the arrowhead type for Dynamo to apply after it selects all of them for the whole model.