So you give the cops a reason to pull you over, naww.

It`s the required size per DNR but okay

I think federally documented is a lot more common on the coasts than it is in the midwest. I do like the foam ones you posted. I have been pulled for paperwork checks, but don't start no shlit, won't be no shlt.

In some cases, it can help with avoiding local taxes. I had receipts that stated my boat was stored for a majority of the year in Florida vs. Virginia; AND when it WAS in Virginia, it was stored/"garaged" in a county and (mailing address) an address in a county that did not have Personal Property Tax. I know all states do not have this.
IF I would have had it state/locally registered; the locals would have been all up in my biz.

They look nice but trying to wax around them I think would be a pain.

I have a Montana and Wyoming LLC. No state taxes.

The majority of boats at LOTO are documented for tax purposes, but you still have to get MO sticker to display.