In Y0, the locks were operated remotely, while in Y91, as the info pages say, they need to be guarded by on-site troops. The Finns obviously took possession of the canal in a very hands-on way, at least.
Any Finnish mage posted there, however, should be very much aware that the neighborhood is spirit-screaming in Russian, rather than Finnish.
All snickering at "spirit-screaming in Russian" aside, I've always wondered about the language.
Hearty Jane On the Train spoke untranslated Swedish to Emil, the radio static was fragments of Danish and translated English.
The notoros and luring house-troll spoke directly to Emil in what we presume was Danish but clearly enough for Emil to understand and speak with them, although Lalli seemed to think that the presence of Lalli's consciousness in Emil's mind was sufficient for translation.
The mages understand the troll- and ghost-speak directly, regardless of language, and not just while they are in the spirit realm. Sleipnope (a composite of Danish grosslings) taunts Lalli (who doesn't understand Danish) during the battle, "How are you less weak?" Lalli didn't answer, but we presumed he understood the taunt, and then later he confirms the ability to Emil as per the above.
Tuuri experiences the voices in translated format as well, when she manifests the Rash.
Reynir is not shown communicating with any ghost ("uh, hi?" doesn't count), and communicating with Pastor Anne only in the spirit world, where the language is
Westron universally understood. Neither he nor Onni understand Danish.
tl;dr So Lalli and any crew with mage ability will just be hearing, and ignoring, the usual blather. What, if anything, will Reynir hear?