For not too much money you can get drill bits that include a countersink, just pick one that has the center drill the right size for the screws you're using, and set the countersink for the length. Then it's the same amount of time.
For example: (picked at random from Amazon, there's lots of brands and options available, and you can probably find them at your hardware store) https://www.amazon.com/GMTOOLS-Countersink-Tapered-Woodworking-Carpentry/dp/B0B7BHB4VZ/