Generally speaking, you want to wait for your rootstock to wake up and keep your scions dormant in the fridge until using one bud per rootstock to graft.
All 4 ideas can be OK for apples…did you specify the type fruit roots you have coming in?
Letting the rootstock get too dried, too hot, or even leafed out too much before benchgrafting isn’t a good idea.
And even your second point…if you have containers, putting the rootstocks in soil for a year or three is not a problem…I have some roots as much as 6 years in pots and have not yet grafted (they had been small cheap seedling rootstocks ordered by the hundred).
Getting the sap coming up in roots and having dormant scions may be best, but the other options should succeed. I’ll usually graft apples dormant to dormant…in March…but you’re in a different zone…so getting started may be ok…but if not just refrigerate your rootstocks or heel them in outdoors in a pile of dirt of mulch out of the sun until you are ready.
Grafting to leafed out rootstocks may enable you to see if a graft fails or succeeds quicker, but dormant to dormant usually does fine.
Cherries, pears aren’t too picky, peaches more so.
Ryan’s Beginner guide is excellent to help guide your strategy. Also each type of fruit will need seasonal timing for the best results based on when your region begins to approach the ideal optimum ambient temperatures. I like to use the following data and begin grafting when the ambient temperatures approach the lower end of the optimum curve.
I found this data on the internet for various fruit types showing optimum callusing temperatures to ensure a good percentage of viable grafts. So far it has worked well for me.
Dennis
Kent, wa
Nectarines/Peaches – 18-26 deg C. ( 64.4 to 78.8F)
Apricots/Cherries – 20 deg C. ( 68F)
Plums – 16 deg C. ( 60.8 F)
Apples/Pears – 13-18 deg C. ( 55.4 to 64.4F)
Walnuts – 27 deg C. (80.6 F)
Grapes – 21-24 deg C. ( 69.8 to 75.2 F).
Do not forget tissue damage for most temperate fruit will occur at temperatures over 30 deg C. (86 F)
Temperatures either side of the optimum will also work, but the percentage take will be reduced. See graph below for walnuts.
Those pawpaws are perfectly alive and I didn’t get to grafting them during 2021 when they arrived about March. Whenever I feel like grafting them, I will.
Yesterday I attended a grafting workshop in Durham NC while visiting family. A demonstration and lots of good scions! It was held at Seeds, an urban garden in the downtown area. There were about 25 participants. It turned out to be a pretty cold windy day, but a lot of fun!
