I've been doing this kinda thing I do with my hair when I'm washing it lately, (massaging my scalp) except i do it too the root bases, about once a week working my finger down into the soil and massaging it, (before flushing it) occasionally i might snag a tiny root, but no matter, I give her a good rub, and mix up that top well, but your compost is much different than mine, I'm a lot more woody/mossy, whereas yours is more perlite. But it does help keep the roots draining well.
When I do progressive transplants, usually the second pot is the one that fills out the most solid, (the first one kinda just explodes) there about a 1 quart bag and that either gets put into a 2 or 3 gallon pot, depending on how big I'm growing the plant, but the roots in the center bags become super dense, and are at the "root" of my drainage challenges.
You seem like your really set on not disturbing the root base with your methods, and it serves you really well, but I would suggest that if a plant is having some difficulty draining a little disruption is what's actually what should be perscribed. The lesser of two evils.