ESP32 ext. interrupts sometimes not detected

[PythonKai]

Hello MicroPython Experts,

I have an ESP32 with MP 1.19.1.
I'll count slow Impulses from a water meter and gas meter (Impules are glitch free (hall sensor)).
I use 2 external interrupts on ESP32 for counting with IRQ routines.

GasIn  = Pin(21,Pin.IN,Pin.PULL_UP)
H2OIn  = Pin(23,Pin.IN,Pin.PULL_UP)

def GasISR(pin):
    schedule(IRQ_GAS,None)
    
def IRQ_GAS(arg):
    global GasCnt
    GasCnt += 1
    
def H2OISR(pin):
    schedule(IRQ_H2O,None)

def IRQ_H2O(arg):
    global H2OCnt
    H2OCnt +=1

alloc_emergency_exception_buf(100)

GasIn.irq(handler = GasISR, trigger = Pin.IRQ_FALLING)
H2OIn.irq(handler = H2OISR, trigger = Pin.IRQ_FALLING)

In main process a lot of other periphery is used:

• one timer every 1000ms with IRQ
• UART 9600 Bd every sec 400 bytes receiving
• Wifi sending with urequest every 5 min
• I2C reading every 5 min
• One wire Bus reading every 5 min
• and a lot of sleep: time.sleep_ms(xx)

Disables some of the pheriphery above the external IRQ ? (unfortunately I'm not so detailed inside the source code of MP)
I guess it is the reason for missing a lot of impulses.
What is the best way not to miss an impulse ?
Is it possible to start an extra 'impulse count' thread maybe in the 2nd core ? (how?)
Is it possible to use the ESP32 internal pulse count module PCNT ? Unfortunately it is currently not supported in MP.

Thank you for some ideas.
Kai