a t who is trauma-based often has more insight into the intricacies of how trauma damages us, the intensity of our wounds (physically, emotionally, and mentally) and usually will be more client-centered as far as checking in with how the therapy itself is going for us, if it's slow or fast enough, getting overwhelming, etc.
a t who knows about complex trauma will know more about these types of issues than a ptsd t. if you can find a t who is familiar with complex trauma, that may be your best bet. there is still, most often, no diagnosis for c-ptsd as it isn't recognized as a separate entity in the diagnostic manual that t's use. most of us here are self-diagnosed.
best to you with finding a suitable t who will be of help to you. sometimes we start with one, then find out that we can only go so far with them, and need to start looking for someone new to continue our recovery. that's not uncommon. i do hope you eventually find someone who is a good fit for you. love and hugs, sweetie.