Eradicate fittings to be changed from routing preferences on models after they are modelled/connected.
This is a long standing issue with MEP - When modelling, Revit routing preferences have the propensity to correct fittings down stream that are already connected - this generally results in remodelling of fittings because Revit want's to reset the fittings. This costs us so much time in correcting.
Whilst we are aware of the why's and how's I simply cannot understand that this method is "Revit working as indended"
What's even more annoying is that Revit removed the "self-healing" of MEP objects to avoid worksharing issues. That's acknowledged and respected. So why is changing a fitting upstream any different? i.e If we change a radius bend to a square bend - keep it that way (it's been done for a very good reason), if we draw in a transition, do not reset the transition if we are attaching a shoe on the adjoining duct. At the very least give us the option for it to override routing preferences.
I cannot accept that this is an acceptable workflow. It's a pain for all MEP modellers.