what type of material is it ? If it is solid wood then yes the surface planer is an option if your machine is accurate and the final thickness allows this. If it is a laminate or MDF then it's a definite no of course. Sometimes sanding the finish off is the best approach to take as well. The material type and how much waste can you allow for can drive your decision alone but I need more info before I can assist you going forward.
Let me know what the material is, hardwood softwood etc. How much material can be removed?
The material that I have is Hemlock. It is 3/4 & 5/4 material. I will be making boxes out of the 3/4 so it could be taken down to 1/2", but to start with I want to get the finish off. I think it has a poly top coat because it plugs up the sand paper right away.
There is no problem planing that trim but depending on what they coated it with, it could dull your planer blades pretty quickly. The problem with many of the latex paint products is that they contain silica ... which is basically a fine sand. I found out the hard way that planing this stuff off some salvaged wood cost me a re-sharpening job on my blades.