My personal experience is the same issue as your shallow draft (4’6”).
We’ve been at the same exact mooring since 2000, and 3 years ago, someone who couldn’t make a turn in the channel complained about the width of the channel.
This prompted a survey and found that for the last 30 plus years our mooring poles were 2 feet too far into the channel.
So they had to move the poles 2 feet back. This made us closer to the edge of the channel wall. Now at Moon Low Tide, we are just touching the mud with the keel. When to wind blows we can feel the boat stop moving.
I am very aware of the tides when we head out and return, but can’t always be that accurate. So we are careful.
And I do believe I am dredging the channel myself with each movement of the boat as we come and go. But not by much.
As far as the keel being damaged, I haven’t seen any signs of that happening. I do notice that there are no barnacles on the bottom of the keel, where there used to be a few each year. Almost like a soda blasting. But the paint is still there.
My rudder isn’t affected by this change, so thats good news.
As others have stated…be careful not to suck up mud when you start the engine. I don‘t run the engine at dead low tides for this reason. And am quick to shut down if returning during the same low tide.
It just takes some awareness on your part.
For us, we love being out there so much, waiting out a tide is just a time to relax and enjoy.
At a dock, storms will create another issue if its a low tide, not so much for us as we swing in the wind. So be aware again.
All in all, in my opinion, I don‘t think its going to harm your boat.
I‘ve include a photo of our boat at mooring. This is the new location, move 2 feet to the left (yes I said left).
I now have 2 more feet to turn in.
And another added benefit is I now longer get fishing lures wrapped around my mooring lines each year. I was always good for one or two each year. And I have quite the collection now.
I hope the person who complained can now turn their boat.