Are phenylboranes susceptible to ipso or meta substitution?
A SciFinder search turns up very little on this type of transformation.

Qui and coworkers run halogenations of phenyl boronate esters using N-halosuccinimide using gold(III) catalysis. The regioselectivity was essentially 1:1:1 for ortho:meta:para. When the reaction was carried out with other substituents as well, the other substituent's directing group preference dominated the regioselectivity.
Gold(III)-Catalyzed Halogenation of Aromatic Boronates with N-Halosuccinimides

There is one other reaction in SciFinder that is relevant, however I don't have access to the full text (and it's in Russian, so I wouldn't be able to read it anyway). The substrate is a benzene ring substituted with a borane cluster. The reported regioselectivity is 80:20 for meta:para.

Electrophilic substitution in the benzene ring of 9-phenyl-o- and -m-carborane. Zakharkin, L. I. et al Zhurnal Organicheskoi Khimii, 23(8), 1691-5; 1987.