Mantis Healing/buff Targeting sensitivity, any tips, thoughts or preferences?

[PlainLazy4]

Ok so this is just about Mantis' heal/buff targeting sensitivity (like if you go to settings on Mantis and scroll down you find it near the control hotkeys etc), I find that her default 100 sensitivity is to finicky and a bit fickle, I often find myself healing/buffing someone who doesn't need it because they happen to be within 40m of the person I want to heal, but I just cannot for the life of me find the happy medium for it, like here's what I mean for an example;

If its low then you have to look at the target dead on, like crosshair aim at them, for it to pick up, which is fine you have more control over who it hits, great. BUT lets say you've got a flyer, Iron man/Storm or even like Starlord in or about to ult or just someone on higher ground even, so if you're focused on team fight they aren't always in view so if they need healing you gotta flick the camera up to get the heal or buff off, BUT then if it's too high you could miss entirely and heal the person closer in your field of view, I.e. the tank or ground DPS who is under no threat and the flyer or whoever could die. This also applies to any dive characters who are further out then the rest of the team but within range of your heal, so I really just cannot find the perfect mid point for the sens to be on.

So TLDR; I can't figure out the best sensitivity for her healing/buff, too high and you can hit different target if your team is clumped up or someone's closer to you, but too low and you might miss the target you want to heal/buff entirely and then they die because you couldn't heal in time etc. so any help or tips appreciated :)