Which chart decides

A setup can be framed on one chart and executed on another. The targets belong to one of them, and it is worth being clear which.

Framing is not holding

A trade framed on the 4 hour chart does not oblige you to take 4 hour targets.

You read the 4 hour to find the zone. You entered on the 15 minute. The next 4 hour level might be four days of holding away, and nothing about reading that chart commits you to sitting through it.

Reading a big chart is not the same as holding for it.

Targets come from where you executed

Set targets from the chart you executed on, or the one directly above it. That is where the rule in lesson 4 already points you.