To add to the point, I've been noticing many (OEM) batteries which are maintenance free have a welded plastic cap on the vents. Kind of a pain to remove and involves significant prying. Other maintenance free batteries hide the caps under the sticker which is alot easier to access.
I seem to be getting ~10 years from my OE batteries and that's with no maintenance and no checks other than following general best practices (eg. never discharging them) so I wonder if it's even necessary to go above and beyond with these.