Will a treatment shift the shade enough to need re-matching?

Slightly, and mostly through gloss, transparency and saturation rather than hue. Pale and bright shades are the sensitive ones.

The layer changes refractive index and scattering at the surface, so what you see is a shift in gloss, a small loss of transparency, and a small hue drift. Deep and matte shades usually hide it; light, high-chroma shades show it.

Measure it rather than argue about it: colorimeter ΔE plus a visual check against an untreated control, on the same base. Above ΔE 1–2 you will need to adjust pigment loading.

There is a second, indirect effect. Better dispersion raises effective tinting strength — fewer agglomerates, more even coverage — so the batch reads more saturated and deeper. That is dispersion, not hue, and the answer is to cut the loading.

Keep a standard drawdown of both the untreated and treated grade. When a batch or a spec changes, compare panels; it is faster and more reliable than reading numbers alone.