Another thing to keep in mind... at one point when I was 50% a colleague was pressuring me to do something that many of the full-time folks were doing that I was resisting because I thought it was a completely stupid waste of time.
I called my boss and started the conversation reminding him that he had 1,000 pb4uski hours a year and asking him if he wanted to spend some of those pb4uski hours doing what my colleague was pressuring me to do... he responded "Hell no" and it mysteriously went away.
I sort of had the same "back door" push back but it was because I negotiated my consulting based on a weekly rate and not a low one. If I worked an hour, they paid a week. My intention (and theirs) was to focus on very specific projects. In the spirit of original intent I tended to look the other way for short hour involvement if it pertained to the project for which they retained me and accumulated the hours until there was roughly a weeks worth and then invoiced them for a week.