I have cooked 1000's of pounds of corned beef and never taken a temperature. It's done by fork feel.
Guinness water and pickling spice, skip the broth.
I always cook veggies on their own in the cooking liquid after the meat is cooked.
And to add, the tenderloin ain't where you want to be.
When I worked in the city many, many moons ago I lived in Hayward, San Leandro area. A bit more affordable There is a commute, Bart services that well.