Then, can the H9 MAX  load two or more alghorithms at the same time? Or, one effect per time?

These are the power requirements of those products:

BOSS RC-300 :  DC 9 V Maximum 320 mA

ELECTRO-HARMONIX BASS MICROSYNTH:  The Bass Micro Synth’s maximum current requirement is 55mA at 9VDC. The polarity of the power jack is center negative. The maximum allowable power supply voltage is 12VDC

STRYMON BIGSKY REVERB:   Input Voltage 9VDC Center Negative, Required Current 300mA

Let me know if the POWERFACTOR 2 can be suitable, thanks.