I think it's incredibly difficult to speculate in these volatile markets on so short time frames. I doubt it's +EV. Much prefer your stance of picking a spot that feels fundamentally in your favour and perhaps adding in some TA but on a longer time frame. At least that's basically only what's made me money trading in crypto last 4 years or so.

Trading on short time frames lets the feelings come into motion so much more. Greed vs Fear. It often just results in buying back into your position higher or selling lower.

A good measurment for me is to never be over exposed in such a way that you feel uncomfortable not looking at the price for a while. Then at least I feel to much fear and end up making bad calls.