Mark Forum as read vs Delete all baord cookies

Any chance of being able to update to more "modern" times with changing things to marking forum read vs delete all cookies? Thus truly marking all topics as read like on all other modern forum sites?

Do you mean something like the "Mark forums read" link on the forum index page? Go to https://tech.lds.org/forum/ and look at the right side of the page above the top of the forum section list.
It only shows up on the index page, so you need to click "Board index" (top left in the gray header bar) to get to it if you're somewhere else in the forum.

It appears that scgallafent beat me to it. If you click on Board Index at the left of the last menu line just before a post begins, the new screen will have a link on the right side called Mark forums read. Clicking that link will do exactly that.

This forum runs on phpBB forum software, which is a fairly common application for this type of thing.