Background tasks in deepSleep() ?

The WiFi boards and new Original boards both come with the low speed oscillator fitted (LSE) - unfortunately Pico wasn't because the chip in it requires a very specific type of crystal to work reliably, which I only found out just before production.

So if you want a low speed oscillator:

• If you get an Original from the online shop then I can guarantee it's the right one, but as long as the board you buy is a revision 1.4b (you could check with the seller) everything should be ok.
  
• If you get a WiFi board from anywhere it'll be fine, since they all had the RTC fitted.
  
• While the Espruino Bluetooth boards (Puck.js/Pixl.js/MDBT42Q) don't have a low speed oscillator, they do have some fancy calibration stuff that goes on using their high speed crystal, which means the RTC is still pretty accurate (20ppm, which is actually the same as the oscillator in the WiFi board!).
  
  

Also worth noting that the non-Original boards can wake up from the RTC much more accurately (to 1/32k of a second) so the deepSleep issue you mentioned won't occur.