Try editing the contour instead of the font
I've noticed that if I have this problem, I can usually get it to go away if I convert the text to curves, then delete the extra nodes that are usually present at the problem locations.
In my opinion, it'd be better to node-edit the actual contour...I'd leave the font alone unless it specifically needs to be adjusted for vinyl cutting.
One reason is that it might have unpredictable results...go ahead and do the contour, break it apart from the source object and then edit that...when you're done, you're done.
Now, Corel puts gazillions of nodes on its contours, I know. For most spikes, I just delete the single node that went into outerspace somewhere (may have to zoom out quite a bit to find it). Make sure that the base of the spike isn't too "flat" though.
Occasionally, I will marquee select a group of nodes in the problem area and delete them. Since Corel usually makes its contours with billions of STRAIGHT lines, this will result in a big straight line that just cuts across the object you're wanting to contour. I select that segment with my SHAPING TOOL and convert it to a curved line, then I put in just enough nodes to allow me to manipulate the line segement like I want (so that it's a clean contour)--it sounds all complicated, but once you've done a few times...it's not that bad.
It's not wrong to adjust the font first...I just see that as being a trial and error type thing...contour's not right...adjust font...contour's still not right...adjust font...etc., plus you wind up with a font that's not quite what you started off with.
I might be making a mountain out of a mole hill, though. Do what works for you.