Hybrid cube business rule optimization

Is there any documentation on business rule optimization for a BSO hybrid cube. We converted our BSO cube to hybrid and started noticing efficiency issues with some business rules (some rules run for hours when they finished in seconds). Everything else was left untouched (no change in storage properties etc.), so it isn't related to converting dimensions from stored to dynamic.

Also, are there any settings that help speed up the business rules that use cross dim operators in the hybrid mode?