This is a kind of micromanagement that doesn't really add anything of value to the game experience. There are far more interesting tests of an advanced player's skill than whether or not they have the stomach or patience to constantly alter their cities' focus every time something is about to be completed.
Somewhat inexplicably to me, it seems this problem is still around in more recent Civ games. As recently as Civ5/Unciv, you still can gain substantially by altering your city's worked tiles just before production is finished on a given city project. This is made quite a bit less tedious by the citizen-managing governor systems added to later Civ games. However, the problem is still there; the micromanagement has just been delegated to altering the governor focus every time instead of individual citizens (when the governor is behaving how you want it to anyway, it's not nearly as good as Freeciv's).
The obvious and straightforward solution to this source of micromanagement is to simply carry over the overflow from one stage to the next for a given point accumulation system. To Freeciv's great credit, it has done this for production where most (all?) other Civ games have not. Better yet, it has done it for research bulbs as well. In Freeciv there is no impetus to dramatically change your civilization-wide luxury/science/gold proportions every time you're about to finish research because bulbs are not wasted.
However, the problem remains for food. When a city in Freeciv is about to increase in population, it is advantageous to rearrange your citizen activity so that they only produce enough food that is necessary to reach the next population stage. Under the classic Civ rulesets, this source of micromanagement could basically be ignored upon switching to Republic or Democracy governments and reaching pop 3. Cities can grow through celebration and it's possible to tell the governor to prioritize other citizen activity while keeping food at around +1. The micromanagement for optimal play is unavoidable, however, in rulesets like civ2civ3 that remove celebration-based city growth. Somewhat interestingly, this seems to be the only form of overflow micromanagement that later Civ games have actually addressed by adding food carryover. Freeciv has not sadly.
So my request is simple: finish what Freeciv started for other point accumulation mechanics and add overflow carryover between population states for food. Alternatively, add the option to retain food overflows in initial game rules or rulesets so that players can choose for themselves--though I have no doubt that just about any informed player would choose overflow carryover when given the choice.
One final potential alternative means of addressing this source of micromanagement would be to build some new logic constraint in the governor optimizer to not set citizens to work on more food than is necessary to reach the next population state. That might be an interesting game addition, but of course the carryover option is much easier.
A long post for a rather small change request, but I feel this is an important game mechanic improvement that needs to be justified.
