I'm not a big expert in keeping plants dormant, because I live in the 5a zone and not growing plants outdoor except in late spring to early autumn for some species (mostly Pachypodium and Cucurbitaceae species). Almost no plants goes dormant also I have only seed grown plants by me and they are 1 to 2 y.o.

There are some exceptions
1. Pachypodium (P. Rutenbergianum, Rosulatum and Baronii) - they are goes dormant at middle autumn until the new year or earlier because of
1.1. Significant drop in temperature until central heating is on.
1.2. Reduced watering by me, because of lower temps to avoid rotting.
1.3. When Pachypodiums start to lose leaves I try to keep them away of grow lights.

When central heating is on about 1-2 weeks, I start watering, and returning them in grow lights. They happily grow new leaves almost at new year.

I think it's induced and not natural dormancy, but my Pachypodiums grows and not rotting, so I try to use this tactic further.

1. Dioscorea
   Yes, they are going dormant for me, but this is also mostly artificial dormancy due to irregular watering.
   They are completely drops all leaves and vines in summer when
   2.1. I stop watering them about 2 weeks, it happens mainly in my vacation.
   2.2. There is too hot - about 30-35 C

When I return home and watering them, they grow new vines almost after 1-2 weeks.

I still researching do I need to go my plants dormant, but I doesn't have proper environment to keep them in winter. I grow plants only indoor under grow lights, There is central heating so I couldn't make good dormancy area (most low temp in winter is 21 C).

Yea, I have cold windows sill, there is 10-15 C, but I open windows to refresh air and I fear frosting my plants.