Hi
Spoolup works great, as long as Spirit is not seeing any wrong signal.
Out of hold, immediately a signal above 50% is required, otherwise spoolup process starts from this mid point. There is an issue with futaba receiver sending some wrong signals causing Spirit to start spool up from a wrong starting (idle) point. Issue got fixed by Tomas, but I don't know if its released yet.
viewtopic.php?p=14561#p14561Maybe if you got same problem, get in contact with Tomas.
I did my setup the way ESC doing spoolup, but Spirit for the governing and Autorotation Bailout.
I still believe it's the safest way and it really works great, I got 30 or more flights with this setup and AR training with no issues.
viewtopic.php?f=17&t=1364To be sure to not get into ARB activation, stay below 11,5% in you diagnostics screen for Hold. All what counts is what you see on diagnostics.
above 49% is Gov engaged, once Gov was engaged and you stay above 12%, ARB is active with fast spoolup, once TC goes below 11.5% next spoolup is normal.
In regards to Values below 0% on diagnostics.
Map you throttle to match 0%..100% on diagnostics, this will be mapped by Spirit to your min max setting towards ESC which are hard limits.
Which mean, values below 0% on diagnostics will not give any lower signal to ESC, as 0% is min range (think of mechanical Limit on combustion Servos) and beside, the hole FBL Setup concept is about min max ranges (rudder, cyclic ring, pitch,...)