Regarding your gate: it doesnt require a bylaw at all and to get it changed it should be prese(n)ted to your committee for their approval and record of the decision to help the integrity of the building and help stop a bunch of individual owners all negatively and piecemeal fashion devaluing your building.
Section 108 of the strata Act, plus sections 142, 143, 144 and 145 clearly state that changes to common property to benefit a lot owner can only be made following a special resolution and the creation of a by-law that may transfer responsibility for the upkeep of the common property affected to the lot owner.
Since it appears that the gate is at least partly owned by the OC, legally, it’s probable that a by-law is needed but practically, there may be a way of either working around that or, at least, getting a common property by-law that doesn’t require the expense of two lawyers and a special meeting.