Hi there
Am reluctant to stick my oar in with experts about, but just til they come back, try this for swallowing (taught to me by bf counsellor):
Look at baby's throat, hard to explain in words exactly where, but below the ear and more or less level with the chin.
When he's feeding, watch the movement there. You'll see his throat move regularly in a particular way for sucking, and then a different way for swallowing (and you can probably hear the swallow too).
So at the beginning of a feed you'll see suck... suck.. suck... quite quickly as he gets the letdown going.
Then, with (hopefully) a fast milk flow, you'll see suck...swallow...suck...swallow.. ie lots of swallowing relative to sucking.
At the end of the feed, the rhythm will change again to something like suck...suck...suck...swallow... pause...suck... suck... suck... swallow.
That way, you can keep tabs on how much he's actually swallowing relative to sucking which in turn is a measure of how effectively he's feeding.
I was advised that the way to maximise feeding and boost milk supply was to watch the swallow rate, and as soon as it slowed down, to swap dd1 to the other side, and keep swapping as long as she wanted to feed. It worked well for us.
Hope that helps, much easier to see in real life than to describe so apologies if my description doesn't make much sense! Also, I'm happy to stand corrected by people with better knowledge!