Roadmap: control smoothing says what's built in audiodsp

ROADMAP.md

@@ -7,12 +7,12 @@ way on every interpreter and board.
 
 - Control moves that ramp instead of stepping: Mix, levels and depths over
   20 ms in audiodsp's nodes, then filter corners, then crossfaded patch
-  changes. The policy is in [docs/how-it-works/control-smoothing.md](docs/how-it-works/control-smoothing.md).
+  changes. [The policy](docs/how-it-works/control-smoothing.md).
 
 ## Later
 
 - Every effect compared with its counterpart in hexefx_audiolib, adopting that
-  algorithm where it does measurably better on our tests. Licences are
+  algorithm where it does measurably better on the tests here. Licences are
   respected file by file: GPL-3.0 code informs a design and is never ported.
 - CabinetSim with real cabinet impulse responses, if their licence allows
   shipping them. Until then they serve as a reference for the synthetic one.

docs/how-it-works/control-smoothing.md

@@ -10,7 +10,10 @@ own tests show Mix moved in 127 steps, one a block, steps the output by less
 than one and a half times the steepest step of the tone going through it.
 
 The rest of this page is the policy planned for the effects, so that a jump
-stops clicking by itself. None of it is built. It is also on the
+stops clicking by itself. None of it is built in the effects here yet.
+audiodsp's `audiograph` `BIQUAD` node already walks to new coefficients over
+`BIQUAD_RAMP` milliseconds, 20 by default, but these effects drive
+`audiobiquad` directly. It is on the
 [roadmap](https://github.com/PyDevices/audioeffects/blob/main/ROADMAP.md).
 
 ## Which controls will ramp, and for how long