easyWDW did a post on May 3rd called 'Spending the entire day at DHS' that included this question. Their recommendation is (and until Toy Story Land opens) currently to arrive at the tap lines by 8:10am. (i.e. you have already made your way to security, gone through security and moved to the tap station lines. I normally allow about 15-20 mins after leaving car/bus to do these steps just in case it's busier than I anticipate). By 8:25 all lines were already backed up past the covered area and heading towards security so by then you're going to wait longer
Another tip, when you follow the CMs walking towards TSM, go through the WIDE archway on the right where the DHS sign is near The Little Mermaid, not the narrow arch on the left. This will make a big difference.
Hope this helps.