In this explanation I will use EURUSD as an example.
The suffix is simply the name of the chart. For example, a broker has a chart that is plotting the high, low, open, and close, for EURUSD. The broker can name the chart anything it wants but the chart is still plotting EURUSD. So the fact that the name of a chart has a suffix attached to it doesn’t mean the currency being plotted is different, it is still EURUSD. Having said this, any EA for EURUSD created by FSB or EA Studio, will trade properly when attached to any chart plotting EURUSD no matter what name the broker gives the chart. So, to answer your question FSB doesn’t need to attach a suffix to the end of the EA it creates and will function normally when attached to any chart, no matter the name of the chart, as long as the currency pair being plotted is the same as the EA created by FSB.