Please offer the choice of "Wipe Out Workspace" already when you enter
/job/U-Boots and not only under /job/U-Boot/ws/. It took me a while to find
this feature and it is my opinion as important as thinks like "Changes".
Alternatively you could offer not only a "Build Now", but also "Build clean
now" option.

(Sorry if I did not select the correct Subcomponent. But I am new here.)