the relevant concern is not script execution time, number of scripts, or script memory, it is collisions. collisions contribute to the overhead of a region and therefore to its lag. how much is acceptable, or not, i don't know, and that is anyway a subjective factor i think. i do not have estate manager access anywhere currently to gather statistics, tho i have been told i can be granted temporary EM if i wish it, for the purpose. but with or without statistics, i am merely asking for an option to have cats that move, without colliding. there are animals that do this and do not fall from where they are set, i just don't know how much work is involved in making it possible, but it is what i would like as an option.
From the wording of my covenant, Sanura may be right that 'unattended' movement is more the point, and i can do things that way, but if it's possible i prefer a kind of 'set it and forget it' way.