It would be preferable to access the DeviceList without it being converted to text and then back into a list.
If the DeviceList is really a list, what datatype are the elements of the DeviceList? It seems that each element contains a BLE Address, Name (optionally), and signal strength. Would these attributes be in a list format to access individually if they weren't converted to text? Dictionary?
This is a design decision that has always bugged me as well. Unfortunately, going about fixing it is a bit difficult because extensions do not have upgraders and so if we change the return type of the property without being able to rename it, existing code may break without manual intervention from the user. Eventually once we fold the extension into the core components we should be able to resolve some of these issues.