What ESR value is considered to be bad?

Depends on the Value of capacitance as you can tell from the meter
chart.

How many times the bad one has to be larger than the good value on the meter's chart?

The times depends of the type of cap, there are low ESR caps and low
leakage caps. Towit the higher ESR the less ripple that cap can take
out compared to a low ESR. of the same value of capacitance. The Lower
the ESR the better.

Good luck
KC8OJU
Raymond Borowiak