For tasks where runInTerminal == false, Tasker waits for the task to end (or for the timeout to elapse) before going on to the next action. This is also what I expected with runInTerminal == true, but what happens instead is that the task continues immediately. See attached video where Flash "Outside" happens as soon as the terminal is launched.

Not sure whether this is a bug report or feature request. If this behavior is unintended, then it's a bug report. I think, however, that the most user-friendly (and least surprising) thing to do, would be to add an option to wait (or not) for the termux task to finish before running the next action, regardless of runInTerminal.

Also pinging #16 which is related.