I think the primary harm with using too much water is that you have to heat all that mass which costs more energy. And I think the secondary risk is: if you had enough water infiltrate a jar, it could eliminate the head-space and cause your food-stuff to exit, which leaves a trace at the rim between the glass and the sealing lid, which increases the chance of a failed seal. In your position, I would just be sure to test the seals before opening to make sure they're not compromised.
(And oh yeah, like John said, welcome to Permies!

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