You don't want to mix them my friend. Its because they have different release times of esters and a high MG/ML will cause pain.
The 400mg your describing I promise you will cause pain. You should just do more frequent injections.
The Deca recipe is good, there are a bunch I have tried and true. Deca is a substance that will do well with low BA and low BB in GSO.
My recommendation is filter the gso, add Bb and then add the ba to the deca, add the gso/bb mix to the deca, slowly heat and swirl.
let it cool so you don't destroy the filter and then filter it. DO NOT OVER HEAT IT, 112 degrees is plenty, I suggest a warm water bath with a stopper and a needle to vent it.
you can make deca at 300 like this with no issues.