I’ve done a version of my sequencer which works with a clean JUCE_8, and on Linux.
And it is a bit more clean.
So it should compile, if put in the same directory as the Audio Plugin Host : extras/, in JUCE repository,
with the Makefile I added. So it’s here : Making sure you're not a bot! .
Of course there is the display problem explained in : AudioPluginHost on Linux : plugin window display problem - #4 by bgg .
I secretly hoped that someone who knows well JUCE will look at it, and give me a few advices.
I’d like to concentrate on my ideas and I’m a bit bored to struggle with JUCE : I struggled with Components, opacity, bufferedToImage, top windows, resizeableWindows, etc. to have an almost working thing, without redrawing everything. There are still a few glitches, but it is usable.
I realized that the TextEditor I used as console was unusable on Linux : after a few lines it becomes so CPU consuming that my program is unusable. There are several posts about this problem.
On Windows I did sessions of hours, with thousands of lines without clearing it, without problems.
On Linux it makes the UI not well responding. It looks a bit like : User input events delayed (Juce >= 6.0.5 on Linux) , sometimes the keypress event is not taken into account, until a mouse move is made … Without the TextEditor it is usable. I liked this console, so I’ll do it in another way.
In debug it’s not very smooth, but in release it is usable. I don’t know why, on Windows I use the debug version without problems.
I didn’t manage to use the AudioProcessorGraph of JUCE 8 : there are now unique_ptr, and a auto-sorted container, and it breaks my way of loading a graph : copying/moving the nodes in an array, clearing the graph, and reputing the ones that are still there : all the mess with unique_ptr makes some processors disappear.
After weeks of tries I simply kept the AudioProcessorGraph.cpp and .h of JUCE 5.
Once again, I did an effort to share it, secretly hoping a little help from someone who knows better JUCE 
I’ve not yet test it with Windows10/11, but I’ll do it. I’ve made my program on an offline Windows 8, and I didn’t want to break this working version. So my code is full of #if JUCE_5, and I set #define JUCE_5 !LINUX.
As I said I’ve did it for myself, and I yet didn’t write clear explanations. If someone wants to dive in, the simplest is to come on IRC. Or one has to read my messy and not completly translated README_en.
Btw it’s better, obfuscated like it is, as I didn’t want my ideas beeing stolen.