Looking at the readme for 3 alpha 11 I can see:

"Tuner AF can be turned off properly now. (Hopefully. We haven't
been able to test it thoroughly.)

The following tuner settings can be tweaked in the config file, in
the "[radio]" section:
"search_level", defaults to ((60*65535)/100)
- min signal strength to stop on when seeking
"ta_switch_level", defaults to ((60*65535)/100)
- min signal strength to change to if there's a TA
"af_switch_level", defaults to ((50*65535)/100)
- min signal strength to consider retune for AF
"

Can anyone confirm that these changes really work ?