In my opinion, it is a myth that you can't run LOP in a Bonanza unless you have GAMI, an engine analyzer, and digital FF. Although I am a great fan of all the above and have them installed in my aircraft, as long as the engine runs acceptably smooth enough for the pilot when operating LOP, all is OK. If your aircraft doesn't run smooth at these mixture settings, then the engine analyzer will help you determine why. If you don't have an engine analyzer, and the engine runs unacceptably rough LOP, just richen the mixture to your normal ROP setting. GAMI injectors definitely will give you a smoother running engine and will save about a half a gallon or so per hour when ROP and they make LOP operations much smoother on most TCM engines.
I have totally gotten out of the habit of using my JPI to set the mixture, it is solely for troubleshooting and pointing out problems. I set the fuel flow as the primary means of leaning by using the analog gage to get close and the digital gage to fine tune the fuel flow because the digital lags, while the analog is very repeatable even if not as accurate. If you don't have a digital FF indicator, reduce the analog fuel flow with the mixture until the IAS drops 3 to 8 Kts. If you notice the CHT drops 20 or 30 degrees F, you are lean of peak.
If you have an engine that runs too rough for your comfort when LOP, then don't run it that way or buy the GAMIs. A good percentage of stock IO520s will run LOP without modification and a greater percentage of IO550s will run LOP without modification.