I am with you on this.
Wood is very forgiving, steel is a nightmare. Everything else is in between. Our 1/8″ bits are very inexpensive, I say save the machine and dull the bit. I had to buy plenty of cheepie 1 time use $80 end mills for projects I could see where these things would start to matter. We are using a relativity flexible machine, so things are a bit different. Just know when metal is involved you will get work hardening, other than metal you can really play it by ear. Have fun, don’t worry too much about it. When I set up a cool project I tend to experiment with feeds speeds and depth as I go. You really start to get a feel for it quickly. Plywood was buttery smooth, MDF was a lot tougher to cut, unexpected for me.
Although when you do get chip load correct this is when the machine experiences the lowest loads, and the best cuts (other that tiny slow passes). For us I think spindle speed is the biggest one to play with, we are kind of set in the feedrate.