Chris, I have an Sieg X3. Before I added an auxillary high speed spindle I used to cut wood with the main spindle at 200 rpm. It works OK you just need to take keep the feed rate lower than with a high speed spindle. (experiment on scrap wood)
Link to video of my X3 cutting wood:
https://m.youtube.com/watch?v=vjOMwEOcJbQ
For engraving aluminum I use a half round engraving bit from Little Machine Shop
Engraving Tools, Half Round, Individual Sizes 4318 - LittleMachineShop.com
The little engraving bits want a higher RPM too but I have always run mine at 2000 rpm.