This is really good, I can see that a version of this could be used for ‘Where can you go for £2’ or similar. If it is to be useful more widely than the enthusiast community it probably needs more detail in the touristy areas and less in the busier areas.
A few more thoughts, even though I haven’t had the chance to get this up on a big screen
Scarborough to Bridlington main service is the 12, the 13 is seasonal.
North of Hull the X46 and 121 run together as far as Beverley which is worth a mention.
From Boston the purple routes are technically B3, B5 and B7.
Frodsham is marked but not named.
Definitely add in the X18 via the coast between Alnwick and Berwick.
If you can fit it in I would also add:
West Wirral, 22 Chester to Heswall and West Kirby also routes across from Liverpool to those places.
In the Lake District add Ambleside, show the open top 599, also the summer service Windermere to Penrith, 30 south from Workington to Whitehaven
In the north east add Ashington, Blyth, Whitley Bay, Tynemouth and South Shields and some key routes joining them and to Newcastle
Maybe, if touristy, the 680, 681, 688, AD122 from Hexham and Haltwhistle
Perhaps Hornsea and Withernsea in East Yorkshire
72 Skipton to Grassington
The X4 Middlesbrough to Whitby via Redcar and Saltburn, as suggested above, also 81 Redcar to Guisborough
Anglesey add Amlwch and Beaumaris from Bangor as well.
I think you could move Harrogate and Ripon a bit north to sort your Ilkley and Otley issue.
These are minor and suggestions - it’s great.
I never knew of the 93 from Bingham to Grantham by the way - thought this was a train only corridor!
Oh and between Rhyl and Denbigh it’s the 51, not X51 (but goes through)
And from Todmorden it’s the 590 to Rochdale and the 591/2 to Burnley, there 3 go east to Hebden Bridge and Halifax. Given the high profile of this area at the moment you might try to add in the 901 to Huddersfield and/or the B3 north to Keighley - this might mean moving Keighley a bit.
It’s easy for people like me to suggest adding things but in the end it’s a balance between detail and usability, your decision where to draw the line (ho ho ho ).