What alternatives are there to sanding resin parts with fine details?
desktop tumbler/brass polisher, rotary rock tumblers are probably a better option than a small sandblasting cabinet. choose your abrasive material from there, a coarse sand is probably not what you want but there are walnut based things and finer grit materials that should be able to get a nice shine. if you would rather do it manually and geometry allows you can try a dremel-type rotary tool with a buffing wheel or similar