To read about alternative sources for traction batteries, click here . Boiling over should not be a problem on a properly filled cell during a gassing charge. If it were, the problem would still exist the NEXT full charge. I prefer to water before a good charge. The gassing helps mix the new water into the electrolyte.
Stratification can cause significant loss of capacity.
Acid on cell tops can be insidious - but you don't find out until your clothes come out of the laundry. If you work a lot around lead acid batteries, invest in some surplus Army woolen OD's. The acid won't touch the wool. My comments are based on being chief engineer on two diesel electric submarines. I used to own 250 TONS of lead acid cells.