Operations Manager is out of the box a good product, but with every good product comes some limits. Luckily with Operations Manager you can work around some of those limits with some neat tricks. For example to exclude members of a group from a group. Up to what limit are such solutions supported by Microsoft, or in other words: when do you lose support when you implement certain solutions and is there a list what to do or not to do?
Direct changes in database : not supported
XML hacks in Management Packs : supported?