Klutzy and heavyhanded, perhaps,
TOS: "The Mark Of Gideon"
at least brings up the not-often explored trope of overpopulation. TOIS season 3, in some ways, was using anything no matter how seemingly taboo. Just not always to ideal effect... or good effect... or any effect other than "This is bad and in some ways it shouldn't have to be" effect.
As usual, season 3's need to do bottle episodes necessitates some creativity - this time it's a group of aliens who managed to get their hands on the Enterprise's schematics and simulate with complete accurac--
Ugh, I can't even finish that bit, and the only point of that "trap" was to get Kirk into the plot.
Despite some direct ribbing of various things, the one thing the episode was sidestepping was sexually transmitted diseases. Not just because of 60s censorship standards, but there is more than enough left open to make some nifty conclusions. Seriously; the Gideon leader wants Kirk to infect his daughter with a form of cooties that he has immunity to but nobody on Gideon does, with the belief that said cooties would cull the entire population - and without once thinking "Duuuuuuuuuurh, will this affect us in the council chamber too?"
The story operates around the asinine idea that everyone has boinked and oinked so much that every traipse-able patch of surface is now taken up by the populace. The underlying reason that nobody dies is because their organs and cells regenerate also resolves the teensy plot point of Kirk infecting everyone on the planet to kill them because they'll get a fever, lay down, flame up just like Doctor Who (so stand around and whip out that big bag of marshmallows and twigs - mmmmm, toasted marshmallow

) , and then pop right back to life to entertain some more. (Note to self: "Day of the Dove" did the same trope of preventing death
just a tad tons more creatively...)
To say nothing of useless things like crops and water and foodstuffs and things, but if their bodies magically heal and never die then shoving anything down their throat is pretty much a pointless thing to do... yet they go right on breeding, which is equally pointless. (I'd say "fruitless" except they're more than fruitful on this weird little planet... and don't tell me that the Ba'ku are on the other side, either...) This story has no real focal point or center of gravitas. It's hard to take enough of it seriously. At least the episode doesn't play it up for laughs out of a sense of clumsy self-awareness.
The Tribble peddler, played with elated jubilance by Stanley Adams, co-wrote this episode. He also wandered around as a gigantic carrot in "Lost in Space"'s arguably best-ever episode. I sometimes wish he took more notes while walking around as Bugs Bunny's next meal.
One of the council members returned to the show, in TNG's 11001001 as Cmdr Quinteros - it's not a big role, but it's a far better one.
All having been said, I didn't expect some nifty camera angles used when filming in the Gideon council chamber, making use of the glass desk and a carefully-angled camera. This is pretty cool and adds rather a lot to a script that's largely making a mess of its core theme (population). Like or dislike or anything else about the episode, they still eked out enough time to have a modicum of creativity, rather than just pointing four cameras across the stage and announce "Action" as if they're watching a painted desert get drier.
What's left, oh dear... :
TOS: "And The Children Shall Lead"
TOS: "Elaan Of Troyius"