You definitely would have figured this out eventually, but the back buttons are SUPER handy and you can remap any games controls on the fly! I personally hate pushing the thumb sticks down as a button, so I almost always remap those to the back buttons.
Also you can adjust the graphics settings on the fly (three dots button on right) and then move up to the battery menu to see their impact on real time.
Under no circumatances should you do that to a Lithium battery. That’s a relic from NiMH battery era and was done for specific reasons you can find online.
Fully draining your Lithium battery will shorten its lifespan. Many new devices have a way to even limit the max charge and keep the battery in the optimal 60-80% range.
I can't say that this wouldn't help in some extreme buggy scenarios where the battery mgmt is not able to report / read the current actual battery status, but it would be the last thing I would try and do to resolve such issues.
EDIT:
reading through the comments in the thread you linked, even OP recognizes that it did pretty much nothing but corrected a visual bug on the % of battery available.