You can feel free to disregard any suggestions you don’t agree with. It is your observation after all! Also, iNat does stipulate “at a moment in time”, and we generally use the date as a differentiation for that, but if the organism changes significantly over a shorter time frame than a day, then absolutely hours should be a better differentiation!
Try this, for linking observations that have some sort of connection to one another, but stopping short of creating a project for them. Some of us use it for lepidoptera raising: