It would be really useful when looking at a summary of a bunch of bugs in NEEDINFO to be able to see which ones haven't been updated for months, and then be able to do an 'update multiple bugs' on them to close them all as CANTFIX. Would a 'Last modified' column be hard to add ?
This is already possible. When running a query and viewing the resulting list, look at the bottom of the page. There is a link called 'Change Columns' or something like that. Click that and on the next screen checkbox next to 'Changed Date' then Save the change. It will reload your last query and show a new column that will display the date that the bug was last modified. Hope this is what you are looking for.