Here is the article you need to read 
Also, if you afraid fail too much at once, you should forge 1 by 1 instead of 9 at once.
I usually do 5- 9 at once, because i know its a gamble move, and if i success i will get a lot of good items for long time.
Also i usually prepare the boon removal solvent to remove the boon i don’t want.
At the end, the bow u get there is not bad, debuff bow is really useful on higher tier planet.
(My highest forge rank is 310, merlin got 390 rank yesterday i think.)