I don't use Pi, Pi is for mathematicians, I use 355/113

Why not 22/7? Close enough, and it's engraved in my brain since childhood.

Anyway, I almost never use Pi, when I have to I hit the Pi key on the calc.

For the rest, it's essentially mental calc, so I would use either a very approximate 3, or some workarounds, like knowing omega for 50Hz is 314, or 1k/1nF results in 1.59kHz.

Considering component tolerances, 3.14 or 3.14159 do not make any difference in analog circuitry.

An accurate Pi value is important only in digital filters.

Sorry for being serious.