With only spoilers for roll control it meant that holding an angle of bank (including 0 deg) using the control column as per 'normal' light twins while asymmetric was a no-no. Spoilers reduce lift & add drag so not exactly desirable to fly with a spoiler cracked open. Better to wind in aileron trim so that the roll trim 'ailerons' would hold the desired AoB, leaving the roll spoiler closed except for transient inputs.
CASA also requires additional training for flight into known icing in them.