T-Rex: Way to tell the miner to solve large 4+ GB shares only?

Is there a way to tell T-Rex miner to only request larger shares three four plus gigs? I noticed after a couple of months of mining that the difficulty during mining changes quite a bit and the miner pauses lots of times causing a huge delay. If there was a way to keep the minor continuously mining smoothly by working on bigger shares I would think we could get more mining credit per day because we'd actually be getting more work done.