On a 219 × 123 mm plate you can typically fit 20–40 standard 28–32 mm tabletop figures depending on supports and spacing, or a smaller number of larger busts. The important point is that MSLA cures a whole layer at once, so a full plate takes the same time as a single figure — print time depends on height, not quantity. That is what makes this size worth having if you sell prints.

They share the same 12K panel, the same build volume and the same footprint, so print quality is comparable. The Ultra adds Tilt Release, a heated resin tank, an AI camera and 150 mm/h against 70 mm/h. Those are reliability and throughput upgrades rather than quality ones. If you print occasionally, the Saturn 4 is the better value; if you print most days, the Ultra pays back in fewer failures and shorter cycles.

The Mercury Plus V3.0 is the direct match — its adjustable brackets take build plates up to 10 inches, so the Saturn 4 plate goes straight in. The Mercury XS Bundle also works, but you must remove the build platform first and wash the parts separately, because the Saturn 4 plate will not fit its tank. If you want to hang the plate itself, choose the V3.0.

Yes. 12K at this plate size is the configuration most commercial miniature and model sellers use, and the COB plus Fresnel optics keep exposure even so that corner parts match centre parts across a full batch. The limitation is throughput rather than quality — at 70 mm/h a tall plate takes a while, which is the argument for the Ultra if volume grows.

Only if that room is genuinely ventilated and you do not sleep in it. Resin off-gasses during printing and IPA off-gasses during washing, and concentrations that are fine during a ventilated day accumulate overnight in a sealed room. A garage, workshop or utility room with a window works well. Note that enclosures and carbon filters reduce odour but do not effectively remove VOCs, and keep the machine out of direct sunlight, which partially cures resin in the vat.