Rod where reel sits into the blank?   That's been done..  Research Shimano Beastmaster rods - late 80's.  These were pretty neat rods and I don't know why they were discontinued.

 

I'd like to see some sort of easily adjustable count down timer that I could set for 10 seconds, 20 seconds, etc.   Bjuild into the rod, or the reel, I wouldn't care.   I'd like to get more consistent timing the drops while I'm jig fishing, especially in water deeper than 10',  but I am not a big fan of cluttering up my mind by counting seconds while I am fishing.

 

Any aftermarket count down timer I have found won't do intervals of less than a minute to start.  That is way too long and not applicable to what I want to do with it.

Any aftermarket count down timer I have found won't do intervals of less than a minute to start.  That is way too long and not applicable to what I want to do with it.

A stopwatch or some kind of an app for a smartphone