The main role of the instrument file is to provide common data that spreads across .tsf files.
Both the TemplateSignature and Parameter classes use delegation to reference commonly shared read only metadata. TemplateSignatureMeta and ParameterMetaData contain all the values which cannot be changed by the user unless the underlying file changes on disk
This metadata is cached in a hashtable in TemplateSignatureFactory to save memory and avoid parsing the file on disk every time.
This has required us to add a new variable for meta data storage so as not to loose backwards compatibility with the old cache. We can still use the old variable to successfully load version 2.1 Ob's