Longer default power-up delay

See MarlinFirmware/Configurations#78

Marlin/Configuration.h

   #define PSU_ACTIVE_HIGH false     // Set 'false' for ATX, 'true' for X-Box
 
   //#define PSU_DEFAULT_OFF         // Keep power off until enabled directly with M80
-  //#define PSU_POWERUP_DELAY 100   // (ms) Delay for the PSU to warm up to full power
+  //#define PSU_POWERUP_DELAY 250   // (ms) Delay for the PSU to warm up to full power
 
   //#define AUTO_POWER_CONTROL      // Enable automatic control of the PS_ON pin
   #if ENABLED(AUTO_POWER_CONTROL)

Marlin/src/feature/power.cpp

   lastPowerOn = millis();
   if (!powersupply_on) {
     PSU_PIN_ON();
-
-    #if HAS_TRINAMIC_CONFIG
-      delay(PSU_POWERUP_DELAY); // Wait for power to settle
-      restore_stepper_drivers();
-    #endif
+    delay(PSU_POWERUP_DELAY);
+    restore_stepper_drivers();
+    TERN_(HAS_TRINAMIC_CONFIG, delay(PSU_POWERUP_DELAY));
   }
 }
 

Marlin/src/gcode/control/M80_M81.cpp

     #endif
 
     #if DISABLED(AUTO_POWER_CONTROL)
-      delay(PSU_POWERUP_DELAY); // Wait for power to settle
+      delay(PSU_POWERUP_DELAY);
       restore_stepper_drivers();
+      TERN_(HAS_TRINAMIC_CONFIG, delay(PSU_POWERUP_DELAY));
     #endif
 
-    #if HAS_LCD_MENU
-      ui.reset_status();
-    #endif
+    TERN_(HAS_LCD_MENU, ui.reset_status());
   }
 
-#endif // ENABLED(PSU_CONTROL)
+#endif // PSU_CONTROL
 
 /**
  * M81: Turn off Power, including Power Supply, if there is one.