Currently have 2010 iMac running 3 extra monitors, 2 with the Plugable USB adapters. Considering going to a mini for the Fusion drive & upgraded speed. Can I run 4 monitors with it, using the 2 USB adapters? While surfing I bumped into a speck that said the HD4000 could only support 3 monitors and I was wondering if anybody had any more info. Thanks.