Have the A7Riii (and the Olympus E-M1miii) and I really like using the C1-3 mode dial settings to change a lot of parameters, including AF modes and drive mode.
e.g. C1 is small focus area, AF-C, low speed burst
C2 is larger area focus, AF-C, medium/hi speed
C3 is like C2 but with AF-C-trk...