I just let LastPass know that I felt similarly by sending them feedback (via their ticketing system here: https://bit.ly/1SFDuZS
Here is the message I used, in case you want to do anything similar:
This is related to all implementations of LastPass, but I chose Chrome browser extension, since that's what I use most.
I would like to suggest that after logging in to LastPass initially, when I then try to open one of my sites immediately, I should not be re-prompted to enter my master password for sites where I've:
A. Required re-prompt
B. Set a period of time (e.g. 5 minutes) where re-prompt should not be required.
This causes me frustrations daily, and in my 5 years of being a paying LastPass customer, that's added up to thousands of frustrations. Please fix! You'd make me and many other LastPass customers much happier.
And to wit, here are all the SEPARATE forum posts on this topic (yes, that's how desperate I was to find a solution. I searched the forums high and low for a solution):
Thank you sincerely.