MM111 is also a little big for me. It does however seem verry adapted to almost all soils. And is reletivly disease resillient. So im doing a lot of interstem (MM111 with M9 or B9 interstem)
I root most hardwood cuttings in a larger flat boxs with lid. Fill 1 side up with damp coco-peat. And lay the cuttings horizontaly, with the bottom in the coco-peat and the top free in air. You can aerate the box a few min every day or few days (usualy twice a week). You won’t need to add water.
I use clear boxes that i place in a dark closet (darknes seems to favor root instead of leaf development)
Once you see roots, i pot up the cuttings.
The moisture content in the coco-peat seems to be really inportant. I get better roots in the more aerated and coarser coco-peat.
Don’t add to much water when using the dried coco-peat bricks
if you squeeze a handful you want to have just 1 or 2 drops of water coming out of it, feels to dry. But it is not, trust me. For me, this happens at adding 3-4 times the weight of the compresed coco-brick in water
In this topic i shared a picture of grape graft+cuttings i did that way.
If your going to regraft and you have enough scion-wood. I would cut off a bit of MM111 stem and the graft and try and root it. And than use the extra scion-wood to graft lower on the remaining MM111 rootstock.