In Cornell commercial guidelines they recommend using a scab fungicide somewhere from green tip to tight cluster and if I’m putting down oil anyway it seems like a reasonable thing to add myclobutanil.
Here’s something from UMass that supports what you wrote partially but not whole heartedly.
"An orchard with no scab on the orchard floor, and no sources of scab within 100 ft., has a very low risk of scab infections early in the season. Research out of the University of New Hampshire has demonstrated that in these low-inoculum blocks, the first scab fungicide does not need to be applied before pink, or until the first three infection periods have occurred, whichever comes first. This may save one or more fungicide applications in the block
This is a radical departure from the recommendation that fungicide applications should start as soon as green tissue appears on the apple tree. After all, it is early-season infections that have the best chance of exploding into significant scab problems. And with increasing resistance to the most effective eradicant fungicides, the sterol inhibitors, an epidemic that does get started will be more difficult to stop. We recommend that growers use the delay approach conservatively. Rather than delaying until pink, or until the first three infection periods, delay until tight cluster, or the first two infection periods."
From Cornell, (1) “From Pink bud to Petal Fall we get major spore releases while the green tissue is expanding and this means that the target on which the apple scab fungus ascospores can land on to infect is increasing rapidly,”’
Which suggests that an app at tight cluster would still be offering protection a couple days later when pink begins to show.