A lot of what we eat is not ‘recognized’ by the body, like cellulose (a plastic, can you believe that) that is found in abundance in ‘healthy’ foods. It’s in no way harmfull, it just transits and goes out by the bottom.
Transfat is, like all fats, quite digestible. It’s supposedly harmfull not because it’s not ‘recognized’ but probably (there is no solid physiology mechanism behind that, just some doubts based on some epidemiological observations, ie the lowest of scientific evidence) because it’s an unsaturated fat and hence more oxydable and more inflammatory.
I’ll stay away from margarine and other trans fats; butter seems much more natural and healthy:
https://pubmed.ncbi.nlm.nih.gov/27215959/