Hi @dpps
As long as you cover the areas where air may enter to the carpentry, you’re good to go. You can cover with green florist tape, electrical tape & do it at the same time while tying your scion onto the tree branches.
I put parafilm on scions and leave plenty of room to cut and then cover all the exposed areas with tape or parafilm (whatever is in my hand at the time and not my pocket) or if I have tons of extra parafilm that has gotten old and doesn’t stretch worth a darn anymore.
So, my approach is to carry a knife, rubber budding strips, electrical tape, and parafilm. I carry pruners and a hand saw in my back pocket. I wear a simple nail belt that’s 99cents from Menards. My supplies are in a bucket (extra tape, extra this and that; bandages, etc) and a small hand cooler with ice to keep the scions from cooking while working outdoors field-grafting.