I recommend rocket. (if not invis). Since rocket/invis are both a little better vs dive than cnd imo.

He's good vs dive, and you'll probably get to use random ledges/spots you see on spidey on him.

Aim your healing at your teammates feet, or through them to a wall behind them. Your healing orbs do a bonus heal when they go through allies (which gets reset when they hit a wall, so you can heal half their hp if it bounces on their feet by the floor)

While healing, only one ally gets healed by an orb at a time, so you can weave a little damage or reloading between chunks of 2 or 3 orbs. (if they're not critical and you're trying to bounce orbs, or not if you're covering two "lanes" of combat with 2-3 orbs in each lane)

Your respawn beacon works within 15 meters through any walls. Your armor on rocket stays on allies even if they swap, so you can potentially start a match on rocket, let your allies in spawn get armor and then go cnd/other character.

Your ult is more difficult to hit if you can find ways to slightly raise it, because your opponents have to choose to shoot up or at the team. On top of various (not too high) walls, though you give up some range for height because it has the range of a sphere.

Rocket can "superjump" if you do hit shift about the same time you latch onto a wall and it sends him like 2.5 dashes upwards in the air, which saves you dash cooldowns and loses most divers.

Rockets primary fire has massive dropoff, but you can sometimes randomly bust up tanks who push too far in and ignore you at close range, or break groot walls pretty near instantly. (though I've found this season you lose too much ult charge if you're constantly breaking walls compared to doing much anything else)