I know this is the nichest of topics on an already niche but growing forum.
I've been playing diatonic for a couple of years and have been working hard on getting a tuning system
that works for me.
I play mostly English dance tunes and the problem I came across early on was the C#s in the tunes in G.
I started with G Paddy richter which worked really well but no bent C#.
Couldn't figure out Paddy richter in D and I'm still at a loss there.
I then found Melody Maker in G, now this works for D tunes.
I also had a go with Fiddle tuning on a G Chrom but couldn't settle with the way it's set out.
I then found G major cross tuning, this was it, I could easily bend the D draw on 6 down to C# and all the notes from G3 up to c5 are there

For tunes in D I tried D Major cross but it ment learning new places for the same notes .
Then I thought why not just sharpen the Cs on the G Major cross and make it a G major cross melody maker tuning..
For me this works brilliantly, patterns in G and D are the same and I've got my C# accidentals on the G.
This is how it looks.
Major cross in G.
Blow G B D F#A C e g c e
Draw A C E G B d f#a b d
'MM' Major cross in D.
Blow G B D F#A c# e g c#e
Draw A C#E G B d f#a b d
Let me know what you think.
Nick