Hey Damo!
Oh yes, now I remember - I was watching the stream, too!
No worries about not catching that sooner - sometimes it's helpful to have a fresh set of eyes looking at your stuff.
In terms of organizing the videos, I just meant perhaps having a couple of playlists as
their own sections on the front page (looking at your three playlists, I'd put the "Dyspraxia" and "Developmental Language Disorders" ones on your front page and you can always switch those out as you make more videos and playlists of course). Here's an example of a gamer I follow who has his videos organized into different sections to give you an idea:
https://www.youtube.com/c/notOtzdarva
As for what I was saying about the thumbnails, I was just giving you a suggestion about making your thumbnails visually tie together with your banner and branding/logo (for instance, your thumbnails are primarily dark and purple while your banner and logo are lighter, blue, and green). Here are some examples of what I'm talking about:
https://www.youtube.com/channel/UCT2RrVhQhJBr6h-cfWCFhAA (similar photos and fonts used)
https://www.youtube.com/channel/UC_htUlq7eYumecIoQai4HzQ (similar fonts and colors)
https://www.youtube.com/c/TubeBuddy (even in ours, you can see how the red to purple gradient is featured in both the banner and many of the thumbnails)
Of course, you can take or leave any of my suggestions - I hope that something I said was helpful to you, though!