Just speaking in "extremes" of the scenario ("If...the two walk into a bar...). Keep in mind that there is sort of a scale of grey, so this isn't the defining, but maybe some caricature for the sake of illustrating that they can have vastly different practical implications.
R2K extreme - Sharp distinction between the sacred and secular
In practice, this could lead to either inconsistency between what a person might purport theologically, and what they may actually do when faced with social or 'secular' applications. Alternatively, this could also lend to some wishy-washy-ness, especially in matters that are not as clear. In considering how a person should act in their local community or social arenas, how a person should vote (if they should vote), in matters of stark practicality like business or economics, etc--a logically consistent R2K-er is going to have some difficulty in separating the spheres when so much of life--even in these 'secular' matters can involve moral aspects--thus bridging the two spheres (church and state) they're trying to separate!
Neocalvinist extreme - Blurring of the sacred and secular
The opposite end of the spectrum is neocalvinism, which at its worst could boil down to 'if it's all sacred, then none of it is.' This is where you get the caricatures of Christian blog posts redeeming outright-sinful (or in the least highly questionable on the conscience of a Christian) movies, or some of the examples that were given in the thread already (the attempt to "Christianize" people, places, things--you name it. I think this also under-girds more subtly some of the more broader evangelical tropes of making a 'Christian' item--if you slap a verse, a cross, or a fish on it...that being the baby-step version to really 'reforming' the whole system. I think this is a popular thing to grapple onto for younger generations (source: am a younger generation) who are all about changing the world (and all such things that young people dream of), and the way to do that is to be relevant to society....but instead of calling it 'trying to be relevant' we mask it in hyper-Kuyperianism and call it "redeeming." I like this quote that is MIS-attributed to Luther oftentimes: “The Christian shoemaker does his duty not by putting little crosses on the shoes, but by making good shoes, because God is interested in good craftsmanship.”
I like to think that a balanced view falls somewhere in the middle of the two, recognizing that God's redemptive work is powerful enough to encapsulate the whole world--even caring for the lilies and the sparrows (so should we not also care for those things?)! That should move us to work his redeeming love in our lives. However, there are specific, sacred acts that Christ has called us to be a part of--he is a holy God, after all, and so we shouldn't forget that holiness requires a 'setting apart'. That said, Christ's work in our life should be evident in our whole being--from bedside to business (even if we don't stamp on seals of redemption and fishes. Sometimes...a painting of a cat is just a painting of a cat.