I've used auto acrylics a lot. I've used wood dyes, stains and fountain pen inks. Used Tru Oil a couple of times. Tru oil is slightly yellowish which is fine over natural timber or darker colours but does show up on binding (Whatever they use at the Gretsch factory does too) where auto acrylic doesn't. So far I haven't had any shrinking or cracking but my house is temperature stable all year round and they never leave here. I have katana sayas here (sheaths) I painted with auto paint 10yrs ago and still look great, the saya is generally magnolia wood. Don't know of where I could buy nitro around here and I don't have good enough breathing gear to be spraying 2 pack. As I said elsewhere I have no option but to spray outdoors , usually early in the morning before the breeze comes up.
I'm sure some others will disagree with my processes but everyone has their own methods and standards I only build for my own amusement..