diff --git a/docs/bounds-track-plan.md b/docs/bounds-track-plan.md
index 747387c..5954b4f 100644
--- a/docs/bounds-track-plan.md
+++ b/docs/bounds-track-plan.md
@@ -89,15 +89,27 @@ They land together, with the manager claiming only for drivers in an explicit
 Delegation is delivered in `onHello`. That works for a driver that says hello, and
 **two of the four do not**.
 
-6. **`ps2-bus` and the `acpi` service never hello at all**, and that is deliberate:
-   device-manager.md records "Legacy drivers (e.g. ps2-bus) are supervised and
-   restarted but **not yet required to hello**", and the `Driver.speaks_protocol` flag
-   exists to say so. Delegating to them means either making them speak the protocol —
-   promoting them out of "legacy", which is a change to their documented status — or
-   giving the grant a second delivery point that is not `hello`. Neither is written
-   down. A second delivery point would also need its own answer to "when", since the
-   whole value of `hello` here is that it is the moment the driver is known to be alive
-   and is a synchronous point to hand something over.
+6. **`ps2-bus` does not hello**, and that is deliberate: device-manager.md records
+   "Legacy drivers (e.g. ps2-bus) are supervised and restarted but **not yet required
+   to hello**", and `Driver.speaks_protocol` exists to say so. Either it leaves
+   "legacy", or the grant gets a delivery point that is not `hello`.
+
+   **The `acpi` service is not this case — an earlier version of this question wrongly
+   lumped it in.** It is spawned as `addDriver("discovery", no_device, false)`: the
+   *discovery service*, one per firmware, with **no device assignment at all**, which
+   "finds and claims the acpi-tables (or devicetree-blob) node itself. Not a per-device
+   driver." The manager cannot hand it a device because discovery is what produces the
+   device tree — there is nothing to match against yet. Its question is not "should it
+   hello" but "is the bootstrap exempt from D6, or does the manager claim the
+   acpi-tables node and pass it on".
+
+   **A delivery point that needs no hello already exists in the shape of the code**:
+   `process.spawnSupervised` returns the child's pid, so the manager could transfer
+   immediately after spawn. If that is acceptable, this question mostly dissolves —
+   `ps2-bus` would not need to leave "legacy" and discovery could be handed its node
+   too. The cost is ordering: the child may reach for the device before the transfer
+   lands, where `hello` guarantees it cannot because the child is the one asking. That
+   trade is the actual decision.
 
 7. **`virtio-gpu` hellos, but best-effort by design.** Its call is
    `_ = device_manager.hello(.device, device_id);` with the comment "Best-effort: