very good improvement from cyanox

include/settings.hpp

@@ -29,6 +29,7 @@ extern float cableOpacity;
 extern float cableTension;
 extern bool allowCursorLock;
 extern bool realTime;
+extern bool keepPreviews;
 extern float sampleRate;
 extern int threadCount;
 extern bool paramTooltip;

src/app/ModuleBrowser.cpp

@@ -192,7 +192,7 @@ struct ModelBox : widget::OpaqueWidget {
 	}
 
 	void step() override {
-		if (previewFb && ++visibleFrames >= 60) {
+		if (!settings::keepPreviews && previewFb && ++visibleFrames >= 60) {
 			deletePreview();
 		}
 		OpaqueWidget::step();

src/settings.cpp

@@ -24,6 +24,7 @@ float cableOpacity = 0.5;
 float cableTension = 0.5;
 bool allowCursorLock = true;
 bool realTime = false;
+bool keepPreviews = true;
 float sampleRate = 44100.0;
 int threadCount = 1;
 bool paramTooltip = false;
@@ -64,6 +65,8 @@ json_t *toJson() {
 	json_object_set_new(rootJ, "allowCursorLock", json_boolean(allowCursorLock));
 
 	json_object_set_new(rootJ, "realTime", json_boolean(realTime));
+	
+	json_object_set_new(rootJ, "keepPreviews", json_boolean(keepPreviews));
 
 	json_object_set_new(rootJ, "sampleRate", json_real(sampleRate));
 
@@ -140,6 +143,10 @@ void fromJson(json_t *rootJ) {
 	if (realTimeJ)
 		realTime = json_boolean_value(realTimeJ);
 
+	json_t *keepPreviewsJ = json_object_get(rootJ, "keepPreviews");
+	if (keepPreviewsJ)
+		keepPreviews = json_boolean_value(keepPreviewsJ);
+
 	json_t *sampleRateJ = json_object_get(rootJ, "sampleRate");
 	if (sampleRateJ)
 		sampleRate = json_number_value(sampleRateJ);