For what it’s worth, by bed has about as much deflection as yours (just in the opposite direction) and I’m getting great prints with the stock Sovol firmware. Not sure what would be causing issues on yours, but it doesn’t look like that’s a universal problem at least.
I believe I saw someone saying you can actually level the bed a bit by adjusting the washers under it - apparently some of them aren’t the same thickness, etc and that can cause some of this deflection in the bed.