Thanks Jase, David
Your not wrong with Ha being hard to bled. I think the key is to get an unserastanding of what is actually happening behind the scenes when blending, how it effects colours and saturation. The rest is experimentation and getting it to look good as per your own taste.
I certainly still have my L plates on when it comes to CCD Mono imaging and processing, but its these sort of challenges that makes all of us who have taken up this hobby appreciate its rewards.
Mark