No. I ran 70% cross with reverse caster back when 60% was considered high. The main thing with reverse caster is you have to start with at least 2.25" of front stagger. If that is too much the kart will push coming off. Reduce front stagger by 1/4" at a time, reset your numbers. Once you find the sweet spot you will be gone from the pack. The main thing with reverse caster is that it allows you to cut under someone coming off and it just not bind the kart. That speed coming off lets you shoot down the front straight and as that momentum builds you just run away. One note: I always used 1/4" drop spindles. I always wanted to keep the washers on the front as even as I could to increase adjustability. You will also need to adjust your cambers a little. A lot of people do not want to fool with front-end adjustments but that is where you will find some real speed.
I know there are people out there who say front stagger has no affect on a kart. Front stagger does all kinds of things with the way a kart handles. It changes the roll angle (tilt) of the chassis at the front. It changes the pitch angle (front to rear tilt). And all of this changes weight transfer which is what we want to manage.
Anyway, give it a try. Just be ready, the steering feed back in the turn will be different. Once you get used to it you will love it!
Msquared - Understanding Chassis Theory and Dynamics