You mustnt have many leaded windows then ?? one scrim on them all day would look bad, try adding some bright sunlight, recipe for complaints if ever there was one!!
Never had any complaints for scrimming leaded windows, even if i went in after to do the inside - i didnt have to go and re do it.
Its not what you use, its how you use it!
Still im wfp now, much easier..
Personally i never liked using microfibre - it wasnt big enough compared to the scrims.