It's best not to bump. Choose correctness over concerns about trivial refinement. If you're making a significant enhancement then bumping is not so bad. Having correct equations is far more critical than rewording an awkward but otherwise correct sentence.
Trivial bumps for attention is most unwelcome. Editing answers or comments within 5 minutes is fairly great, it still causes a bump but since it's not recorded in the 'Edit History' you're making less of a mess.
It's like the Murphy's Law of SE answers: "One must submit the answer to immediately realize it needs refinement.".
Compose using the answer box then cut and paste it into a text editing program where you can spell check, see 'the big picture', or simply save it while you think more or do some research.
I find that the tiny answer box is part of the problem, it seems to have a 'resize grabber' (bottom center) to expand the 'answer area' but that doesn't work on mobile. If you're on a MathJax enabled site that box is still quite useful and you can always see the preview below.
With a lengthy and complex answer it can be difficult to scroll up and down (on mobile) over images and links for fear of clicking on something - fortunately it asks if you're sure you want to leave the webpage.
I've had an answer box sit open for more than a day while I took time to research, eat, and rest; don't worry about it closing on you, in fact when my browser crashes (sometimes MathJax overload, combined with having over 100 tabs open) upon restart my answer is almost always repopulated into the box.
Some answers are difficult and involve a fair bit of research and confirmation, reasonably this can take more than one swing to get it correct. If can see that I have most of the answer(s), and the question is a week old and unanswered, I will post an unpolished answer with a disclaimer that most sites and people respect:
<sub> Note: I have proofread this but will be returning for another edit in a few hours.
Note: I have proofread this and it's finished, there's no need to misread what is written and make an unnecessary edit as has occurred already.