Always do your cropping in Topaz Photo AI. If you crop in Lightroom then send it to Topaz, you are sending a smaller file. If you send the full file, crop inside Topaz, and then upscale, the AI has more pixels to work with.
Have a 12-megapixel crop that needs to print at 24x36 inches? Topaz Photo AI can upscale images by up to 6x without the "jaggies" or pixelation. topaz photo ai