Currently, each Thread Group has it's own rampup, threads, duration, etc. properties. Where a test plan has multiple thread groups each one must be configured separately and this is time consuming and prone to error. 

An option to allow a global default value for these properties would simplify and improve usability.

Something similar to the HTTP Defaults Control would be perfect.

Note. The workaround to this problem is to use variables and point each control at these. But a defaults control would still be an improvement over this.