Workflow 2.0 was a fantastic addition to Microsoft Dynamics GP; I've expressed before my delight at the retirement of Business Portal. Workflow 2.0 was introduced in Dynamics GP 2013 R2, was then further enhanced in GP 2015 and the roadmap shows further enhancements will be coming in future.
However, there is always room for user suggestions for improvements to functionality which is where the MS Connect site. Penny Compton has logged a suggestion that the workflow for PTE Timesheets be expanded to allow individual lines to be approved by the relevant project manager.
The suggestion can be found here where you can also cast your vote.
If you have an MS Connect suggestions you want publicised, contact me with details.