Splicing dehumidifier drain line into AC drain lines

I recently added a dehumidifier in my crawl space and need to add a new line to deal with condensation water. My AC system has two drain lines, one primary and one secondary, both 3/4" in size. The primary line has a cleanout (a tee and a plug), while the secondary doesn't. They both exit the house at the same spot, side by side. Both my AC furnaces and dehumidifier are located in crawl space.

My plan is to splice my 3/8" drain line (coming from a condensation pump) into one of these AC drain lines to handle condensation water, but I could really use some advice on which AC drain line to use. I found a YouTube video featuring a professional installation done in my area where the installer spliced dehumidifier drain line into one of the AC drains, so presumably it's not against local code.

I'm leaning towards using the secondary line since it sees much less traffic. However, I want to make sure I'm making the right choice to avoid any future issues. Any advice or insights you could share on this would be immensely helpful. Thanks a bunch in advance