The problem with support Wisp/support frames in general is that if you're already going into endgame content, you can usually expect your team's kits to already be sufficient for that content. You can increase their survivability further by making use of shock motes to stun enemies and rad procs but this typically just slows down missions (especially the shock motes in defense missions) if they're used in situations where they aren't really needed, and can cause issues with builds that make use of enemies clumping together like if you're trying to make use of Gas/Blast or have a Harrow in the squad trying to buff with Covenant. Rad procs from breach surge usually aren't as much of an issue though.
If you are willing to give up fashion, you can subsume Elemental Ward and use a green energy colour for a reload buff to complement Wisp's Haste mote, along with the Everlasting Ward augment mod so the buff is actually useful to your team.
Breach Surge is a lot less useful now that enemies are often protected by overguard, ignoring the blind effect and being immune to the CC effects of Radiation procs, I think they might even be immune to friendly fire too (they aren't targetted, and I think they're immune enemy AOE attacks like a Bombard's rockets). You can still try to make use of it though, there's only so many enemies that can attack at the same time so you can still reduce the number of enemies attacking your team/the objective at the same time.
Pillage/Fire Walker for status cleanse; Pillage gives you Armor Strip at the same time while Fire Walker gives to a movement speed boost for memes. Your team still needs to walk through the flames though but it's a more passive in its use versus Pillage which requires you to cast every time you want to use it. With Overguard being on everything now, status cleansing is a lot less useful, but it was still nice to have for Sorties.
I think you're much better off modding to specialize for your loadout and letting your team pick up the buffs passively instead of trying to directly buff your team.
Probably worth adding that Ivara, Inaros and Titania are the possible warframe choices for the non steel path version of the circuit this week.
Ivara's not a bad choice if you need warframe for spy missions, just remember to also pick up her Infiltrate augment so that you can walk through lasers undetected. Normally requires you to run spy vaults to collect her parts.
Inaros did get a rework recently but his usage seems to have tapered off since then, at least from what I've noticed in public match making. Normally requires Simaris Standing if you don't have the base version anymore.
Titania is a pretty good warframe for various missions, lantern is usually pretty strong for defending excavators/defense objectives. Requires Normally requires Simaris Standing to acquire her parts if you've already completed her quest.