Valkyrie needs a buff for her Threat Vision ability.

In a multiplayer shooter with 57 enemies on the ground I'm not sure that "safe engagement" is the way you want to be thinking about this problem.

You have to assume they're looking at you. Assume they know where you are. Assume they know which way you're moving. Assume they know whether your squad is formed up or scattered. Once you make these assumptions, most of which are probably true in a platinum lobby and definitely true any higher than that, then the path forward becomes clearer. As always, high ground is your friend. Land high. Top of a building, or even a hill if that's all you can find. It's better visibility on them, and less on you. If you have a good mid-range game then you can usually open up with some confidence. And if it happens that somebody does get a shot on you then odds are they're farther away and that buys you time to react.

High ground. Mid-range. That's as close to "safe" as you will ever get in this game. Or as close as you can reasonably expect the dev to let you get.

Edit: And now that I think about it, they recently added the ability to use the missile swarm while diving. That's damage AND stun, basically for free. I still wouldn't, and don't, use it offensively except in rare situations, but I'd say her kit is currently in a pretty good place even for a player who is rash, inexperienced, or aggressive.