I need to get petg down to 18% humidity for flawless prints. I use the stock bambu slicer setting and optimal default print speed. For me the gyroid infill creates wall blobs so I need to use something else for smooth walls. I use a filament dryer/spool and get the petg down to 18% as mentioned, then I reset the dryer timer snd run the actual print with the dryer on. It takes 6 hours for the dryer chamber to get back up to 40% humidity once its off.
Also when you heat up filament with a heated dryer it expands and becomes more porous, so if you turn the heater off in a humid environment the petg is going to cool down and draw in humidity from the air. Consider that before printing.