Your list isn't a bad one, but it doesn't control the volatility of BTC's price, it only limits its effect on the BTC investor who follows such strategies, your post title gives the impression of a discussion on the possibility of controlling BTC's price volatility generally, of which we can maybe mention mass adoption and fewer weak hands.
Yes of course, the subject of this topic is somehow misleading as it sounds like controlling/minimizing the bitcoin market's volatility. I have seen many discussion about safeguarding our investment against volatility of bitcoin market but nothing was helpful to me personally and finally I have chosen long term hodling which is the best approach to protect our investments against the wild fluctuations of bitcoin market.
Dollar-cost averaging: This is a strategy where investors invest a set amount of money at regular intervals, regardless of the current price. Over time, this helps to average out the cost of Bitcoin and reduce the impact of price volatility.
DCA+hodling for years must be a very powerful approach to beat the volatility. Simply DCA for short term may not get you preferred results in bitcoin environment as here bear markets may last for years. So, to overcome the negative impact of volatility, we must need to go for DCA for at least four to six years which will include at least 2 halvings.