Love the table.
Can you follow up with a column for what grafts endured to the end of the growing season? Would be interesting to see the long term viability.
I am doing my own trial with multi-grafting plums and so far all 13 or so grafts have leafed out but at various vigor.
I did go against the recommendation to graft when its warmer (I’m in 7a) and just did it as soon as the tree started pushing growth and a warm spell was available - so far it looks like its working out okay but well see. Especially since we got hit with a low of 25°F two days ago.