I believe the univerbation of τοῦτ' ἔστιν is accented τουτέστιν (LSJ p. 1808, s.v. τουτέστι, citing the TR for Mark 7:2 among others). My impression from reading older editions is that earlier (i.e., early modern) editors of Greek seemed more apt to typeset certain fixed expressions as single words, hence the difference in the treatment among the authorities that Alan is looking at.
I wonder sometimes about πρὀ τοῦ before an articular infinitive. In Galatians, it acts like a lexical preposition like πρίν. Note the position of the postpositive connective particles in Gal 3:23 Πρὸ τοῦ δὲ ἐλθεῖν τὴν πίστιν ... and Gal 2:12 πρὸ τοῦ γὰρ ἐλθεῖν τινας ἀπὸ Ἰακώβου ... . Now, LSJ in its entry for πρό notes that πρὸ τοῦ was sometimes written as a single word:
Should προτοῦ be a New Testament word? I don't know... on the plus side, it avoids having to invoke a weird exception for the placement of γάρ and δέ in Galatians 2:12 and 3:23 respectively.LSJ 1465, s.v. πρό II.1 wrote:π. τοῦ (sts. written προτοῦ) A.Ag.1204, Hdt.1.122, 5.83, Ar.Th.418, Pl.Smp.173a; ὁ π. τοῦ χρόνος A.Eu.462, Th.2.58, etc.; π. τοῦ ἤ, = πρὶν ἤ, IG7.2225.22 (Thisbe)