Welcome justyou,

There are many specific cases (especially chart patterns), which are not covered  by the included indicators. Now FSB / FST can use custom indicators and there is no objective reason anyone to write the desired indicator alone. Of course some programing skills are necessary but there is nothing more difficult than writing the same for MT.

The current opportunities of using custom indicators are to manipulate the price flow. Since the chart formations are exactly that, it's completely possible to calculate divergences and head_and_shoulders.