If you need more show-time then ask for it. I know, maybe we are privileged to do this in our OPS, although me and more than 100 colleagues just endured a rough year with lost jobs and an unexpected return.
The problem is: there are a lot of back-stabbers - if you do not do the job according to the owner's demands, even while being illegal (cheating on duty time), somebody else will do it. I wish we ALL could stick together and create a much better place for everyone where nobody would try to undercut somebody else. It's just a dream, it will never happen, I am aware of this.
Back to the question a few posts before this one: I think you can do a short show, but then everything needs to be organized: take the fuel the day before, be sure that the paperwork is ready to be collected (call FBO before leaving hotel), start your briefing on the way to the airport, delegate work to get everything done smoothly and quickly without missing items. The main threat of short shows is that you may lose sight of important things and it might bite you at some point. It is only possible with an experienced crew that understands the task.
And, of course: for a revenue flight you cannot turn up less than 60 or 75 minutes before ETD. Stand together and get this time on record. Report your company if they continue to cheat.