OK Drifter Rod Holders

Has anyone used the built-in cup holder/rod holder on an OK Drifter to troll?  Seems ok for trout, but I have my doubts about it being sufficient for larger fish.  I have a Scotty I want to install on the center section designed to hold a small plano box, but then I'd lose that perfect tackle storage area.

Has anyone fished a Drifter before, and if so what was your solution?  The position of the cup/rod holder is ideal...  but is it trustworthy?  I was considering putting some sinkers in an old sock or something to hold it in there tightly.  Am I just paranoid?

I've seen the behind-the-seat flush mount holders, but I like to be able to watch my rod tip while trolling.

Thanks in advance.