PLA support material suddenly a problem on Ender 5
As the commenter suggested (thanks, 0scar!), the culprit appears to have been a Cura update and a change to the support material settings. 

In my case, the defaults for Z distance and even the X/Y distance for support material, in addition to the density, was creating very effective supports, but very tricky to remove. I should add that the model was a character sculpture, which I've since learned creates much more complex support scenarios versus the more uniform models I've been accustomed to printing.