Logten Pro Gurus..
I do as I have a couple of custom limit groups that track my company crew duty limits.
I don't think there any quick ways to enter multiple trips. If you use an iOS version of LTP also then you can configure standard duty times. For example my company limits are 120 mins before scheduled off blocks and 30 mins after actual on blocks. You can then just press the small = symbol and they are automatically entered for you. Unfortunately this feature is not currently supported in the mac version.
Also are you aware that for multi sector days you only have to enter the duty start time on the first sector and the end duty time on the last sector? LTP recognises that the sectors are linked and will display the total dutton the final sector.
Hope this helps