The multi-GPU GGUF filter at fit.py:380 returned None unconditionally for Q*/IQ quants on 2+ GPU systems. When the caller explicitly passes target_quant, they are asking 'what happens if I try this?' and expect a structured no_fit response, not a silent None. Fix: skip the filter when target_quant is explicitly provided so the call falls through to the existing no_fit path. Fixes #