I keep promoting it when I can, I linked to it on ReaLinks:
For Heda Mixer, the Graph wasn't as evolved as in Loudness Graph (it's main priority was the mixer part), I'm not sure when Heda's Mixer went to the level of Loudness Graph but it seems now it can definitely replace the old script, being more efficient on every level.
For ReaImGui, I invite you to come on Discord ReaScript, cfillion do a top class support for any reaimgui related question, solving complex issues in minutes. The chat format, the code emebedding with syntax highlight etc allows fast conversation which is handy for dev.
See you on Mixer thread :P