i use iosdowngrade 2-3 times every week ever since 3.4 was launched. I agree with you that downgrade is safe(until boot2v4 came out), cioscorp is good.
but for god's sake, why do you need install cioscorp before you change from K to U? it heard cioscorp set it is own version to the highest version possible to prevent nintendo update wiping it out. it seems it successfully prevented you from downgrading it.
it seems you followed a lot of online guide, but til now you have not yet understood that your first mission is to convert K to U, turn it into a clean U WII, not anything else.
but for god's sake, why do you need install cioscorp before you change from K to U? it heard cioscorp set it is own version to the highest version possible to prevent nintendo update wiping it out. it seems it successfully prevented you from downgrading it.
it seems you followed a lot of online guide, but til now you have not yet understood that your first mission is to convert K to U, turn it into a clean U WII, not anything else.