Although your mileage may vary, and you should seek professional advice before doing anything at home, consult your instruction manual, and [add your favourite "safe harbour" provision here] it should be noted that, in general, lenses have "stops" just to help the photographer set the aperture ring without stopping looking inside the viewfinder or, for let's say street photography, to let him adjust aperture by counting clicks, without even looking at the camera. The aperture ring will normally be settable at any position, regardless of clicks, also on lenses which have clicks. Lenses were created without clicks. Clicks were added later to help Henri Cartier-Bresson (or whomever) set the camera without getting too much attention or without distracting him from the action.

For calm and reasoned work while using an external light meter you can normally set them at 1/10th of a stop if you feel like. Light meters give you values in thirds, or in tenths of a stop because you can actually use those values, normally. (OK they do it also for other reasons such as checking evenness of illumination but I digress).

It obviously makes sense only with slide film to be so precise, but it does make sense with slide film if you like working with exactitude and if you don't like surprises.

Remember that shutter speeds and aperture rings will not necessarily give the exact exposure that they say.

The shutter might introduce a 0.25 stops error, and maybe the diaphragm another let's say 0.25 stops error. Now you also approximate your light-meter reading with another 0.25 error and you have three 0.25 errors. IF you are very unlucky, and those errors are all on the same side, you end up with an exposure which is 0.75 stops different than what you thought.

God knows how much "bracketing" is due to all those mistakes that creep here and there and make the final result slightly unforeseeable when using slides.

The scrupulous photographer checks his shutter's precision, buys good lenses with precise diaphragms (they were not created all equal), and uses the entire movement of his aperture rings (without being limited by "stops") so as to minimize all those rounding errors.

When doing serious work which provides for the soup at dinner, bracketing is also an option