ESP-IDF itself creates different tasks for wifi, bluetooth etc.
Espruino port for ESP32 uses 2 tasks, one for Espruino itself and 2nd for uart console, see targets/esp32/main.c
There has been a first question/idea from @Wilberforce to move some of those tasks to 2nd core.
Don't know if somebody has experience with that.
Splitting Espruino itself into several tasks would be (IMHO/AFAIK) a complex rebuild.
Running 2 Espruino tasks, one on each core, hmm, memory is too small for that.
One could think about supporting SPI, I2C seperately, but again, this would be a complex rebuild.
Some months ago, I asked in ESP32 forum for experience using both cores.
At the end, feedback was more or less a theoretical description, how powerful it would be for example for graphics. No feedback about experiences in own projects.
Looks like 2 cores are not (yet?) used in real applications.