First off - congratulations
on your baby pear trees, and your success with "Crown Grafting!" I'd shown some of my work
at the spring class in hopes of inspiring just that!
Advice; allow each sprout to "go wild" this summer - you'll "tame it" this Winter! And, this Winter you'll need to bend and tie over those sprouts to form permeant limbs. Try to give equal sun exposure to each, or just expect a couple to eventually dominate while the others simply heal the wound.
Your "next project:" (an excellent question) YES
, those stored scions should be perfect
And it's only a few weeks past prime Bark Grafting time. You simply need the bark to "slip," and your scions dormant. This allows you to: make your cut - deep - right into "the wood;" carefully peel it back; insert the scion (I'd suggest leaving only 2 buds); tack it in place using a small nail with a head; (plumbers) putty the remaining gaps, and seal with a latex grafting compound (don't forget to dab the scion tips with sealer). I assume you'll do whatever just worked for you - but that's the basic process.
My first concern would be "sunburn" this "late." But as of late (in Western Oregon) - no problem! But you may want to consider shading the tender sprouting scions of your next project (the 1st ones should be fine) if we get some real scorching
sun. Second; when Bark Grafting, remember, you're working close "inside" the tree where, once leafed out (as now), far less sunlight penetrates. As the season progresses, make sure all the Crown Grafts are receiving adequate sunlight, competition from nearby water shoots is not good. Let the desirable wood dominate!
Otherwise - keep us posted