Yes, this is common practice in some applications.
What they are doing is either superimposing or superexceeding the previous move.
On the MAJ instruction, there is an input called "Merge".
If merge is enabled, the MAG instruction is superexceeded. This means that the MAG instruction is stopped and the MAJ instruction takes over the control of the axis, without executing a MAS instruction. This can be handy if a standstill of the axis is not desired when changing from gearing to jogging the axis.
If the "Merge" input is disabled, then the MAG instruction is superimposed. Which means that you are running both the MAG and MAJ instruction at the same time. This can be very handy sometimes.
I hope this answers your question, otherwise let me know.