It's certainly easy enough to re-calibrate, so give it a try, but keep in mind your depth finder won't gybe with the charts once you've added an offset.
There's only ONE time that a DS will agree with a chart anyway. When the tide is at MLW or MLLW depending on the chart datum.
One is ALWAYS required to do some math at ALL OTHER TIMES.
And don't forget, the bottom usually slopes, right? So all those nice fuzzy lines on the charts with numbers on them are merely RELATIVE and you're usually between the lines anyway.
I understand navigating with depth contours quite well, and have used it often. Yes, one MUST know the height of the tide and make those3 corrections. But please remember, those depths were charted years, decades and sometimes even eons ago.
That's why all navigation courses carefully note that navigation/piloting should use as many different methods for determining position as possible.
I have two areas of skinny water I encounter regularly. For both, I have determined over the years what the tide height MUST BE for me to transit those two spots. Think of it as a DS reading done backwards!
So, as long as YOU decide what YOU like and what works for YOU, have at it.