Do you mean 2% for stop loss ? With high volatilitas of crypto, i think that too small percentace in crypto trading, for the better use minimum 3% to 5% for stop loss and take profit minimum 10%. Stop loss 2% can be better to use in stocks trading that has lower volatility than crypto.
2% trading strategy is not about stop loss, but a way to manage your funds when trading.
As long as you are trading a market and you want to enter a position, it is a normal way of saying you should not use more than 2% of the total amount you have to go in on that trade. That is one thing a lot of people always fail to do anyway and they either go all in, or just do whatever they please when going in on the trade which makes the outcome horrific at times, when things should not go in their favor.
With respect to stop loss, as long as you are not having a higher loss to lower profit ratio, then you are good, so in that case, you always set your own risk when it comes to stopping loss.