[bri3d]

The challenge in single-core timing-important ESP development is using the wireless peripherals effectively while maintaining I/O scheduling. Even with "zero-cost async" at the application layer, the WiFi and Bluetooth implementations are mostly software and will be getting scheduled on that same single CPU. You don't really get to control their scheduling in a granular manner, so meeting timing is pretty hard in many situations.

This is probably the most annoying thing about ESP development, but mostly goes away when you can just dedicate a core to the "ESP stuff" and then run your application on the other core.

[tlamponi]

They are mostly software but the actual time critical RF stack isn't, those esp's have that in HW (at least their manual suggests that) and the remainig Bluetooth or wifi stuff does not need to run in an interrupt disabled critical section, so can work fine with an time critical app, but naturally depends on how much transmissions need to happen and how time critical and compute intensive the application is.