XDJ-RX2 INTRODUCCION MANUAL BPM (TAP+TIME)

I understand your question, but please consider the fact that the recommended audio source for an XDJ-RX2 is music prepared within rekordbox, which would all have a beat grid, thus negating the necessity of a specific time function. It does have a TAP functionality, but if your beat grids are accurate, it's not necessary to use it.

The DJMs have a time adjustment because they are a higher level product, and if a DJ is playing from another (external) source where there is no beat-grid data to lock the effects.