Should you be using arm vibrato on repertoire while learning wrist vibrato?
Should I be using vibrato as normal while I'm training wrist vibrato or should I stop it all? I don't know if using arm while learning wrist will be counterproductive or not.
If your present vibrato is not faulty - stiff, with a gripping left hand, (or gripping chin) - it shouldn't interfere with the new motions practiced separately.
Probably not. Ask your teacher. He/she likely wants you to learn one motion at a time.
I learned wrist vibrato first, but eventually needed to add an arm vibrato for certain situations. (Double-stops, wide 1st finger vibrato on lower strings, etc.) After being stuck for a while, my teacher recommended a "vibrato cleanse" where I used no vibrato at all for two or three days (including no arm vibrato training), then no wrist vibrato for two weeks. That was what I needed to learn the arm motion. After that two-week "cleanse" I was able to work on my arm vibrato separately while resuming wrist vibrato in normal practice.