As I have reminded people many times, disable-dso cannot be 100% effective. In order for disable-dso to remove a scheduled retune event, there has to be a boot process after the retune event is added to the schedule database and before the event triggers. If your 'HDR is left on for long periods, there are no boots taking place. Even if your 'HDR is not on for long periods, there is a finite probability of a retune event slipping through.
The only sure way to prevent a retune event is to stick with firmware 1.02.20.
On the other hand, disable-ota defends against auto-updates, not auto-retunes.