It's not that bad. Over the last couple years have done a more regular job of watering and fertilizing and even without using any weed killer yet this year after a heavy spring overseeding, except for this bluegrass there is actually very few weeds naturally forming in the lawn. Saw maybe a dozen dandelions total and some clover along the border with the street. Overall the fescue has grown in strong enough to look out most weeds, even while I can look across the street and see a yard full of dandelions and those white cup things.
Only negative if the seeming total lake of ability for the grass to repair itself in barren spots. Have one spot little bigger than a softball that is plain soil and still bare. Will probably need to use some patch seed as it didn't catch during the normal overseed.
For anyone else reading the thread, have a question about dethatching. I haven't done it before, and it probably needs some particularly in the areas of the about to be removed bluegrass. Have read some description, but not watched videos yet, so some of this may be simpler than it seems. Saw a dethacher tow behind attachement that was basically small metal tubes attached angles down to ground level. Visually it appear as something just a bit smaller and less deep than if you were trying to till the ground and seems that it could do decent damage to an otherwise good lawn. How does this process actually go?