app.py: smaller QoL updates

app.py

@@ -119,7 +119,7 @@ with gr.Blocks(css=css) as demo:
                 with gr.Tab("Generation"):
                     with gr.Row():
                         with gr.Column(scale=1):
-                            sampler = gr.Dropdown(value="Euler a", show_label=True, label="Sampling Method", choices=[
+                            sampler = gr.Dropdown(value="DPM++ 2M Karras", show_label=True, label="Sampling Method", choices=[
                                 "Euler",
                                 "Euler a",
                                 "LMS",
@@ -160,5 +160,4 @@ with gr.Blocks(css=css) as demo:
 
         text_button.click(flip_text, inputs=[prompt, negative_prompt, model, steps, sampler, cfg_scale, width, height, seed], outputs=image_output)
 
-demo.queue(concurrency_count=5)
-demo.launch()
+demo.queue(concurrency_count=16, max_size=20, api_open=False).launch(max_threads=64)