Hi,
There's currently no way to switch between Hold or Toggle to ADS, other than forcing it by binding both "Toggle Aiming Down Sights" and "Raise Modifier" to the RMB - which is completely inconsistent.
Toggle to ADS feels very unnatural to many people and a way to Hold to ADS has been requested many times over the years.
With the ADS bug solved, I believe this would be a huge QoL improvement.