H3 Studio Switches (feature toggles)

H3 Studio Switches is the labelled panel of feature toggles for the H3 workflows - three live switches (sol-attn, chunked FFN, remote encoder) whose boolean outputs drive the H3 Any Switch gates that route around optional features. It's the place you flip a feature on without rewiring the graph.

The interesting thing about this node is what it kept. It outputs eight booleans, but five of them are permanently false and labelled (removed) - two_pass, spectrum, block_cache, dual_clock, hybrid_cond. That's not laziness. Saved ComfyUI graphs link by slot index, and shrinking the output list would have turned every 2.5.x canvas into a validation failure or, worse, silently driven the wrong gate. So the panel preserves the old slot layout: the three live flags emit their real values, and the five dead slots always emit False, which their gates then treat as the off path - exactly what you were getting before.

How it works

The three switches that actually do something:

• sol_attn - memory-efficient attention. Lowers peak VRAM on large canvases, slightly slower. It's "the 24 GB card's tool for 243-frame windows." Two steps to use: install ComfyUI-sol-attn, un-bypass the attention patch node (Ctrl+B), then flip this on.
• chunk_ffn - runs the feed-forward layers in chunks to lower peak VRAM, slightly slower. Same two steps, same pack, un-bypass the chunk FFN node.
• remote_encoder - encode prompts on a second ComfyUI PC so this card never loads the 15+ GB text encoder. Fill in the H3 Remote Text Encoder node first (address + encoder file), then turn it on. OFF = normal local encoding.

The toggle only routes; it cannot enable a bypassed node. That's the design: the optimizer nodes ship bypassed so a fresh install without the packs doesn't hard-fail, and the switch is what you flip after you un-bypass. The outputs are eight BOOLEAN sockets in the original order.

Installing it

Part of the ComfyUI-H3-Multishot pack:

cd ComfyUI/custom_nodes
git clone https://github.com/jlucasmcrell/ComfyUI-H3-Multishot

Or search H3 Multishot in ComfyUI Manager. Requires ComfyUI v0.30.0+. The optimizer packs are optional: ComfyUI-sol-attn for the two VRAM switches, and the remote encoder needs the pack installed on a second box.

Gotchas

The classic mistake, documented in the README's own changelog: people flipped sol_attn on, saw no change, and reported it broken - because the switch ships OFF by default and the node it gates ships bypassed. If you turn a switch on and nothing happens, you skipped the Ctrl+B un-bypass step; the switch can't enable a disabled node. And don't worry about the five (removed) outputs - they're false forever by design, and the off path they drive is the plain model, which is the correct baseline. Leave them alone.