Video would be great.

One of the few things about tailgunning in general is that you want to leave a small gap going into corners as that allows you not having no slow down only to speed up again. WR and CDR mention this quite a bit and both are good at it.

The other is patience. You seem like a strong rider, and you should have the faith that you can bridge to the main group. At the beginning, make others close down the gap for you. There will almost always be a few riders willing to close down that gap at the beginning. Otherwise burn your matches ~10-15 in when people are shot out the back. Chances are, after 25 min, people at the front will probably sit up as they may be getting a bit tired.