title_body: What is the proper method of tuning PID filters for recent BetaFlight (4.x) on micro-sUAS WITHOUT Blackbox?
upvoted_answer: OpenLager is one solution.
  Tuning with auditory inputs is another (it's usually possible to hear oscillations caused by excessive P or D gains), but this is more challenging.  This is made significantly more challenging because often props are poorly balanced, and this can imitate the same sorts of errors.
  
  Unfortunately, trial &amp; error tends to be the best answer to this.  As far as general trends, in the sliders most often stock master gains, 0.8-0.9 P/D Ratio, and slightly high P&amp;D Gains (1.1-1.2) will work well on quads with good motor authority (1202.5, 1103 >10,000KV for 1S quads).  Thrust_linear = 50 is also something that produces pretty great results.
  The harder one is trial &amp; error on filters - quite often you can work iteratively towards the right with the gyro all the way out to 2.0, and the D term filtering will end up somewhere in the 1.4-1.8 range with these PID settings.