Let's me tell you for Kloxo-MR 7.0:
1. Possible using different php version for every domains
2. How?. Need this follow:
a. Install every php version via 'multiple php install'
b. By default, website using default php via 'php used'
c. For any reasons, better select one of phpXYm (like php56m) instead 'php branch' in 'php used'
d. If want enable/disable modules , use 'php modules state'
e. If want using different version for website, use 'php features'