I feel your "grid" would not be a problem if formed out of say 1/2" mesh hardware cloth. My hatcher has trays---and I have dividers that I place in each tray where needed to keep the chicks separated. These dividers are made out of 1/2" hardware cloth----they cause no problems because I usually hatch 95 to 100%.Well, going in I knew what lockdown meant, but inadvertently created extenuating circumstances. My boyfriend has games but works away a lot & I don't know the different breeds well enough to just leave all eggs in a wide open 'bator, so I divised a grid divider. I was concerned it might interfere, but it didn't seem to on the first batch, so used it again this time around, but had a full load this time. I think this batch is the last one, for a while at least, but in the future I'm hoping to sort eggs into batches I can better identify & so I can do what I'm supposed to do--lockdown & let them hatch. He just may have to wait for more than one batch to get all his babies he wants.
When I did remove chicks & shells to make room, I was quick & it didn't seem to take long to regulate, but I don't disagree that I just need to learn to leave things be.
Biggest problem I'm having is finding "my way"--the incubator directions give some recommendations on temp/humidity, but if you ask 5 people their recommendations, you'll likely get 5 different answers. As far as I'm concerned, it takes time & experience to fine tune what works best. Each incubator is different, as are all the environments those 'bator's are in. Mine behaved better the first batch, but (humidity) gave me fits this time.
I'm learning
Here is alot of the problems about asking 5 different people the same question----some of those 5 are not qualified to answer the question, but they want to help---they give you their way then if you go back and read old post---some of them have never had hardly any decent hatches. I read some bad advice on here and just have to hold my fingers back from typing what I feel.
You say "" while I don't expect perfection in life, I do have a tendency to expect it from myself"" and I feel that is a good thing and I feel you seem to have the desire to "Dig" for the right answer and the right way. I am the same way. I try to help on here---some pay my advice no attention---all I can do is offer----they can do what ever they want with that info. I am venting here----mainly because it takes so much of my time to type all this with my one finger + my spelling is not good----I could be doing other things with my time. Good Luck to you!!