The single needles wil not be ready before December. The factory has promised us "for sure before Christmas" but we have been working very hard to get the needles produced with two factories for the past 1.5 years and also this time it looks there may be complications. As far as needles go, our needles seem to be quite a few steps above rocket science. We still hope and expect to have them for sale just before Christmas though. We are extremely frustrated about the delays but there is nothing we can do.
You can combine single needling, stamping and rolling during the same session, no problem. Usually, it is easier first to needle, then stamp and then roll because when the scars get red from the procedure, they are less visible and it is difficult to precisely target them with the single needle so starting the session with needling is the most practical.
No, you should not needle or stamp scars that were injected with fillers. Microneedling triggers the deep renewal of the skin and this could theoretically speed up the diminishing of the filler. The filler will be diminishing anyway but deep needling could maybe speed it up.
Copper peptides do not really work for pigmentation. You can either try acid peels or a cream with hydroquinone. Or very low percentage Retin-A, applying it with a toothpick on the scars only, to avoid peeling of the entire face.