Battery specific issues

Use the laptop how it is best for you. It is Ok to leave the charger plugged in all the time since the new Battery Management feature introduced with Big Sur now exercises the battery automatically. See this Apple article for more information plus links to articles about proper battery care:

About battery health management in Mac notebooks - Apple Support

I said it does not matter either way since an update to macOS Catalina included the new Battery Management utility which now exercises the battery so that users don't have to worry about unplugging the laptop to manually exercise the battery once in a while.

Cycle Count does not really indicate battery health at all except if the count is high the battery may need to be replaced soon, but not necessarily. Do NOT worry about the cycle count for battery health. The battery's health is always declining as it ages (meaning over time). How the battery is kept is more important such as not exposing the battery to heat or impacts which can damage the battery and shorten its life. Battery swelling is not caused either by leaving the battery charged 100% or exercising the battery. Heat, physical impacts, and just simple imperfections in manufacture of the battery can cause a battery to swell. Plus I've seen batteries which have been completely discharged for an extended time begin to swell once the battery is begins to charge again. The Apple article I linked in my previous post includes its own link on how to properly care for the battery in your laptop (here is the other link contained in the previously linked article):

https://www.apple.com/batteries/maximizing-performance/

Also here is what Apple has to say about Cycle Counts (it does not mention anything else about health being related to cycle count):

A normal battery is designed to retain up to 80% of its original capacity at its maximum cycle count when operating under normal conditions.