toolhead: Reduce target buffer time from 1 second to 2 seconds

During normal printing the host software would attempt to stay ahead
of the micro-controller by 2 full seconds.  Change that time to 1
second.  This should make the software more responsive to user
requests (such as pause requests).

Signed-off-by: Kevin O'Connor <[email protected]>

Author: KevinOConnor

docs/Config_Changes.md

@@ -8,6 +8,10 @@ All dates in this document are approximate.
 
 ## Changes
 
+20251010: During normal printing the command processing will now
+attempt to stay one second ahead of printer movement (reduced from two
+seconds previously).
+
 20250916: The definitions of EI, 2HUMP_EI, and 3HUMP_EI input shapers
 were updated. For best performance it is recommended to recalibrate
 input shapers, especially if some of these shapers are currently used.

klippy/toolhead.py

@@ -190,7 +190,7 @@ def add_move(self, move):
         # Check if enough moves have been queued to reach the target flush time.
         return self.junction_flush <= 0.
 
-BUFFER_TIME_HIGH = 2.0
+BUFFER_TIME_HIGH = 1.0
 BUFFER_TIME_START = 0.250
 
 # Main code to track events (and their timing) on the printer toolhead