To mortise for the face plate, I like to use a fence attached to my trim router with a 1/2" mortising bit. If the fence is set to reference from the side of the door farthest from the mortise edge you are cutting, it guards against cutting past the line. Making an initial relief cut right down the middle, as you demonstrate, makes it much easier and safer to make the final cuts. When drilling the crossholes from either side, it can prevent blowout of the side walls of the mortise if you rip a filler that fits the width of the mortise and insert it to back up the bit as it exits the side wall.
To mortise for the face plate, I like to use a fence attached to my trim router with a 1/2" mortising bit. If the fence is set to reference from the side of the door farthest from the mortise edge you are cutting, it guards against cutting past the line. Making an initial relief cut right down the middle, as you demonstrate, makes it much easier and safer to make the final cuts. When drilling the crossholes from either side, it can prevent blowout of the side walls of the mortise if you rip a filler that fits the width of the mortise and insert it to back up the bit as it exits the side wall.
I saw that same tool on amazon and thought the price was too good to be true, but now you've convinced me it's worth it. Thanks.
Glad I could help!