U get it wrong i dont fish with hp under 99%. U get to fish, and there is a chance a mob appear instead of fishing, and u will have to fight, so your hp will be reduce and the script will equip your weapon and kill the mob, the reequip the fishing pole and continue fishing.
Also u have to preconfigure the fighting policy and the autofishing.
I hope now i answer properly and sorry for my english.
but it u change it to 101% it will always change to your weapon and u wouldnt be able to fish.