But then the missiles won't be flying towards the fixed point.
Take this picture here. The first missile is fired at 0 deg
2nd at 25deg
3rd at 45deg
4th at 70deg.
Even if I have to manually enter the bearing as I fly around the circle, I'm not prompted to do so, nor do I know what bearing I should be entering.
And if they are supposed to be automatically updating their bearing, they don't.
In the included track file, I did set up the missiles to fire at bearing 233, enabled fxpnt on all of them, and they still did not converge on one point. Instead, they flew parallel to each other to 233.
I'd actually suggest you try doing it for yourself. I've not been able to find any videos of fixpoint being employed, and both chucks guide and ED's guide only mentions it.
harpoonfxpntfail.trk