A friend of mine had colon vaginoplasty several years ago. Yes she had lots of depth, but she also had many other complications, which you already mentioned. She told me she had numerous revisions and finally is happy with the results.
It can be done, but colon vaginoplasty is not the first choice for initial GCS. The only reason for using the colon method is not enough penile skin for the normal penile inversion GCS. Even if you do not have enough penile skin, I recommend you first try a skin graft from the inner leg or lower tummy. If that fails then colon GCS is another option.