MBQ Wedge Scheduler

Everyone obsesses over the sampler dropdown. Almost nobody touches the scheduler sitting next to it - most people set Karras on day one and never look again. MBQ Wedge Scheduler is for the day you finally look: one Queue click, one image per scheduler, each PNG labelled with the scheduler that made it.

Why the scheduler deserves a sweep

Here's the split nobody explains: the sampler decides how noise gets removed at each step, and the scheduler decides how much - the noise schedule. ComfyUI keeps them as two separate dropdowns, which is a gift, because it means you can hold the sampler fixed and actually measure what the schedule is doing to your image.

The stock list is tiny - just nine schedulers in this build (simple, sgm_uniform, karras, exponential, ddim_uniform, beta, normal, linear_quadratic, kl_optimal). Nine images is cheap enough that a full sweep is genuinely worth doing once per model, and the list comes from comfy.samplers.KSampler.SCHEDULERS, so anything another pack registers shows up too.

One caution before you go: the classic "just use Karras" advice is SD 1.5/SDXL wisdom, and it stops being wisdom on flow-matching models. Aggressive reshaped schedules can actively hurt Flux-class models, whose near-straight training path doesn't want its noise curve bent out of shape. On an SDXL finetune, a karras vs sgm_uniform vs exponential sweep is the kind of thing you run once, note the winner, and never think about again. On Flux, run it with fresh eyes.

How it works

Identical machinery to the other two wedges: the JS extension intercepts Queue, submits one job per scheduler, and embeds the scheduler name in each PNG's ComfyUI metadata chunk so MBQ Viewer (or any metadata reader) labels the images for you. The output type matches the scheduler COMBO, so it plugs straight into a KSampler's scheduler input.

The filter box is where you'll spend your time. Blank sweeps all nine; or list names one per line - space-separated works too, which is handy when you're pasting straight out of MBQ Viewer's metadata panel. Invalid names get silently dropped and the label shows the real count live ("will sweep 3 of 9 schedulers → 3 images"), so a typo is immediately obvious. parameter_name auto-fills to "scheduler" and labels the outputs; current is just a cosmetic readout of the dropdown.

Install and gotchas

Whole-pack install - ComfyUI Manager search "MBQ Wedge", or:

cd ComfyUI/custom_nodes
git clone https://github.com/Beakfx/mbq
# restart ComfyUI

No dependencies, no model files. And the two wedge rules that always trip people: one wedge drives a sweep at a time (leave two connected and MBQ warns and queues a single normal job), and don't wire this into a sampler_name input - the pack detects the mismatch and yanks the link, because sampler and scheduler dropdowns masquerade as the same type in the frontend.

The scheduler is the half of the sampler/scheduler pair that people skip because fiddling feels like there's no payoff. This node removes the fiddling. Run the nine, keep the one that works, and spend your afternoon on something that isn't a dropdown.