From 4dcd872be54d913d26c95666a74a67efd59a0519 Mon Sep 17 00:00:00 2001
From: Keith Bennett <13375512+thisiskeithb@users.noreply.github.com>
Date: Mon, 1 Nov 2021 21:23:54 -0700
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Allow=20Low=20EJERK=20with=20LA,=20?=
 =?UTF-8?q?optional=20(#23054)?=
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---
 Marlin/Configuration_adv.h   | 1 +
 Marlin/src/inc/SanityCheck.h | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 35602373d2..ba3c2c10c9 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -1913,6 +1913,7 @@
   #define LIN_ADVANCE_K 0.22    // Unit: mm compression per 1mm/s extruder speed
   //#define LA_DEBUG            // If enabled, this will generate debug information output over USB.
   //#define EXPERIMENTAL_SCURVE // Enable this option to permit S-Curve Acceleration
+  //#define ALLOW_LOW_EJERK     // Allow a DEFAULT_EJERK value of <10. Recommended for direct drive hotends.
 #endif
 
 // @section leveling
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index edd12a2885..3287262f0b 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -1246,8 +1246,8 @@ static_assert(Y_MAX_LENGTH >= Y_BED_SIZE, "Movement bounds (Y_MIN_POS, Y_MAX_POS
     #error "LIN_ADVANCE and S_CURVE_ACCELERATION may not play well together! Enable EXPERIMENTAL_SCURVE to continue."
   #elif ENABLED(DIRECT_STEPPING)
     #error "DIRECT_STEPPING is incompatible with LIN_ADVANCE. Enable in external planner if possible."
-  #elif !HAS_JUNCTION_DEVIATION && defined(DEFAULT_EJERK)
-    static_assert(DEFAULT_EJERK >= 10, "It is strongly recommended to set DEFAULT_EJERK >= 10 when using LIN_ADVANCE.");
+  #elif NONE(HAS_JUNCTION_DEVIATION, ALLOW_LOW_EJERK) && defined(DEFAULT_EJERK)
+    static_assert(DEFAULT_EJERK >= 10, "It is strongly recommended to set DEFAULT_EJERK >= 10 when using LIN_ADVANCE. Enable ALLOW_LOW_EJERK to bypass this alert (e.g., for direct drive).");
   #endif
 #endif