Keep Battery Health Management (BHM) on. It is trying to protect your battery against damage caused by being always plugged in. Batteries die by combination of events - deep discharge (below 10%) is the worst one, permanently being on charger next, and number of cycles is really the last. Search in MBP forum here... Many keep complaining here that their battery died with small number (e.g. 80, 150, 200...) cycles on it - after being nearly permanently connected to charger for 2 or 3 years. BHM is trying to reduce this charger damage by trading it for some cycles. Apple knows best how to optimize the battery life.
Your battery can under optimal conditions get around 1000 cycles and still be above 80% capacity.
Now, there are other ways - AlDente and similar apps can limit max charge which may actually be better - but is manual and you need to control it. Generally, LiIon batteries have optimal life time when cycled between ~30 and ~70% charge. If one wants to actively decide what charge he/she will need next time, this may be better.