These aren't KDFWR laws so much. They don't define what a PFD is, the Coast Gaurd does.

So, even if you have a throw cushion on your boat, you have to have a regular pfd in addition to your inflatable? I wear my inflatable at all times while running, but not when fishing. I did notice that the pros do not take their inflatables off when fishing though.
If you take the inflatable off it is no longer considered a PFD is the rough and dirty of it.

The other PFD has to be out in the open able to be accessed. Can't be in a rod locker or other storage. So if you take off the inflatable you need to have your "tradtional" pfd out able to be gotten to.

I usually put mine over the back of the seat. It is out, able to be gotten to, but not in my way. Throwable hangs over my steering wheel as it is in an aluminum boat with no storage lockers.