This small mod allows strike fighters to attack ships with their beam/kinetic weapons if there is a weapon that is better than any of the available warheads.
For example, if you have researched an advanced beam weapon, but only have nuclear missiles (for fun perhaps, or rp reasons, or sometimes the AI does this), your strike fighters won't be forced to use nuclear missiles to attack ships, even though they have a beam weapon available that does more damage.
When intercepting other fighters/bombers, they will of course be restricted to using interceptor weapons.
I guess you could consider this a fix, since I don't see any reason why strike fighters don't already behave like this. Although I guess researching the multi-role fighters tech before getting fusion warheads is pretty rare.
...actually it looks like you need anti-matter before you can research strike fighters, so I doubt this ever happened unintentionally to someone. But hey, here it is.