No I wouldn't wait for spring. If I have a concern; 1., It is the reduced light of winter. 2., Soil mix with very tiny particle size, which holds too much water, and too little air. 3., Placement too near to central heating.
My tender trees get as much light as I can cobble for them (and I believe it to be too little). And my HVAC does not adequately humidify air for trees. Our OP may be in my shoes in this regard too.
Low light levels, makes for bigger leaves with longer internode lengths. Both of which are kind of a fork to the eye of bonsai training, Rig up just as much light as you can. You can always reduce light levels later if you need to.
Figs back bud well enough. As always be a little conservative as you prune, and leave on a terminal leaf on each branch.
When ever you start with saplings, You are building from the soil-line up. A long looping sacrifice branch can be allowed to grow for years to fatten up the base of your tree. An' cause its a fig the sacrifice branch when finally cut off, might just root...
Think like a tree
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