To anyone interested in this topic, I have received confirmation from the pharaceutical company that makes the pill that they can be divided, and even crushed. Although they did recommend taking not long after they are crushed. For anyone this might apply to, what exactly ‘not long after’ means I could not get confirmation. Nor what exactly happens, if anything,when crushed pills are left exposed to air for a long time (days I mean). At any rate no safety/health concerns exist according to them when crushing.
As splitting a pill only exposes a n inner surface of the pill to air, not all its contents , and as the period is typically short (3 - 5 days), I don’t have any reason to believe a breakdown of the active ingredient would occur, which correlates with the accounts and experience of others who divide and crush their finasteride pills.
So in summary, dividing this particular pill doesn’t seem to be an issue. If one has any doubt, perhaps just keep track of whether the active ingredient is active not by keeping an eye on the expected short term effects of the drug.