Who cares how much of it you are converting to other compounds? Its utility will be decided by its being converted regardless, which it will, and by the results manifest in te gym/mirror/feelz.
Its certainly not my first choice of an added compound to trt, but I cant see it being a complete waste being he already owns it, and that it will still convert to useful hormones. At the least adding it in would be like increasing your trt dose. By how much? Dunno, who cares.
If he sold the 4ad and bought some var, or epistane, well thats different.