While playing Pico8 with the native binaries (Splore shows in menu), I can hit the power button to put the A30 into standby mode. However, upon resume I have no sound in game. This happens regardless of whether the Pico8 game is from a local cart or in Splore.
As the option for full shutdown and restore of save states is not available for Pico8, this is the only way to standby lengthy games for later play.