Thank you for the kind words and detailed observations! Thoughtful reactions like yours are really gratifying, and make the effort and time spent thinking of those creative quirks all worth it. :)
All of this was done on Procreate, and were done with a few purchased brushes that mimic pencil grain. Coincidentally someone in the group I shared this with had asked me to upload a timelapse, so I have a short 30-second timelapse and a much longer 30-minute timelapse.
I’ve got time, work from home, and I’d be happy to help if you need it / no one else has stepped up.