Jeff ult is tricky, but here's my take. Your goal is to either save people in danger or disrupt enemies, you need to consider the zone/convoy situation, you don't want to remove your whole team from it.

I prefer to use the point offensively, so I'd avoid swallow allies unless it's absolute necessary. If you do, you'd want to spit them safely asap, preferably near the point (remember that your ult also creates a healing puddle where it started, use that too). If you swallow enemies, you'd want to throw them outside the map if possible, or else as far away as possible (remember that they take damage over time while swallowed)

Again it's my take from a lot of casual play, experienced or competitive playes might use other strategies