Although on that note, while it's not 'banned', flight above the tops of cloud well above the 0Degree even in a twin should be a carefully considered option. Delve into your Operation Data Manual and work out at what height you can maintain Straight and level flight on one engine. You can end in a position where you cannot maintain your clearance from the cloud and end up one engine inop, in IMC, rapidly picking up ice...... sends shivers down your spine... Especially if the onset of ice leads to an inability to maintain above the Safety Alt......
Regards
TGreen