Way too many examples of killer trios where the bass player doesn't do anything but knuckle down and do the job first...hold the most solid rhythm you can and take liberties not as a predetermined route but more as a spontaneous thing. Sometimes it may feel better to lay back and play less, sometimes you lock in and go to town with some killer fills and flurries, but I don't think an effect can make up for loss of sonic tightness. If anything is slightly off or not happening vibe wise it just makes that part of it all louder and more obvious. But all that is subjective to the player so just do that voodoo that you do.....i used to just 'dig in ' and play a little more ... hopefully the drummer is doing the same ...
hopefully the extra digging in would stir up a little more edge/dirt ...
every one needs to help fill the void rather equally ...
. Wonder what else would help the equation?