Understanding mb-tree with ipratio, pbratio

[infoeater]

As mb-tree is supposed to allocate bitrate to blocks depending on how much there are referred, what's it's relation to ipratio, pbratio? Is determined by mb-tree bitrate effectively multiplied by ipbratio?

Is so does it make sense, as mb-tree will give more bitrate to blocks in I and P frames anyway, so using ipbratio instead of making mb-tree stronger will discriminate equally referred blocks based on frame type there are from?

[infoeater]

I am answering my own question - pbratio is currently not processed in x264 if mb-tree is on. Still question to leser degree remains with regard to ipratio.