I wouldn't go so far as to say I ship them, but I do find them to be a good couple if things would ever go that way (which they probably won't). With Kaguya, there's a mountain of issues to be worked through on both sides for their romance to work. Fujiwara is almost the opposite.
I would more chalk this up to Akasaka-sensei being good at writing opposite sex friendships, but there's a really nice compatibility between Miyuki & Fujiwara and Kaguya & Ishigami.
Prez's whole problem is that he can't be his flawed, undignified self around other people. Because Fujiwara is who she is, he's actually able to drop that facade around her. Moreover, because he hits her strong maternal instincts, she actively joins in his struggles every time, and I think having someone join in his struggles is a new experience for him.
On the flipside, there's Kaguya and Ishigami. Kaguya is always on about how she wishes she was kinder and more so than with Miyuki, which is more a relationship of admiration, Ishigami brings out her kindness like no other. Meanwhile, for the first time in probably years, Ishigami has someone like Kaguya put their faith in him, and for the first time in at least as long, he feels pride and shame. Above all else, Ishigami lacks confidence, and Kaguya is bringing that back out of him.