Prefer when it's under the 20 for entry but as we see with Gsat currently it's not necessary. The potential gain should be higher when under 20, my exit target on a swing trade is usually 80 on a daily chart. Usually also use an hourly chart to find the exit, with the very same indicators full sto, Macd and lastly the ADX. A negative Macd cross on the hourly.
In October your example shows that the Full Sto cross doesn't always work alone for an entry. Back in Oct it was at 2.65 on the Sto cross yet still dropped further to 2.20 35%. So the Macd histogram should help confirm entry, the histogram shows the distance between the Macd and its signal line.
Currently Gsats macd is barely above its signal line with a positive Full Sto cross, could break either way. Your example does not have a Macd positive cross and the indicators aren't getting closer as you see with its histogram. Would be careful with that till I saw the Macd start to turn up, the Sto is quicker and could turn back down. just imo