I've did some parts with polyester infusion resin and everything went well, in fact I didn't see any difference, The easy thing with polyester is that you can demould after 4hours if you want to...
Another advantage is the mixing ratio,... just add between 2-4% of MEKP hardener so you cant make mistakes with that.
a negative point is that it is less strong and can indeed get a bit more distortion due to heat. And the smell is realy strong, but you get used to it.
I did some parts full vacuum and did get any boiling polyester or something like that...
If your just doing parts for cosmetic reasons there is absolutely no problem!