Looking forward to the mrtools teacher also adding arrows to the main chart for the Schaff_Trend_rsx_vhf_adaptive_2_4_-_shadow BT2 (fl) indicator:
When the signal line crosses the 80 line downwards, draw a downward arrow on the main chart;
When the signal line crosses the 20 line upwards, draw an upward arrow on the main chart.
Boundless merit!