disable update check:
{
"font_size": 16,
"font_face": "TamzenForPowerline",
"font_options": ["no_antialias"],
"show_encoding": true,
"update_check": false,
"word_wrap": true,
"gpu_window_buffer": false
}
gpu_window_buffer fixed the flickering issue: https://forum.sublimetext.com/t/screen-flickering/43671