Welcome aboard Hugh!
I found Pixinsight quite easy to learn, though I must say I was starting from scratch without previously being used to PS. There's lots of support on the Pixinsight forum. Watching "Harry's tutorials" is a great way to get going.
The repo is nice! Look at all that red channel data
. Did you try the LHE tool using a luminance masked to protect the background? Its a great way to enhance contrast after using the HRDMT tool.