Depends on what you're going for and if you plan on getting regular UOAs to continue tracking trends. When I had the head off on my Fusion for valve work, etc.. I started doing UOAs from the next oil change onward. It has proven a great way to continue tracking the engine following the work.
Admittedly I've not done any tests on this rig yet. But since the oil pump I installed was high pressure / high volume, I want to play around with different oil viscosities to see see if one gives better results than the other. Can't do that while material is shedding though! The pump gives me a fair bit more wiggle room, both to not lose pressure in the Xw20 territory, and not lose flow if I'm going thicker.