Now that you have all of these bugs filed, you have to figure out when to address them. Generally, the right thing to do is to make sure that developers regularly fix some of the code quality issues that you filed along with their feature work.
If your team makes plans for a period of time like a quarter or six weeks, you should include some of the code cleanups in every plan. The best way to do this is to have developers first do cleanups that would make their specific feature work easier, and then have them do that feature work.
Usually this doesn't even slow down their feature work overall. (That is, if this is done correctly, developers can usually accomplish the same amount of feature work in a quarter that they could even if they weren't also doing code cleanups, providing evidence that the code cleanups are already improving productivity.)
Don't stop normal feature development entirely to just work on code quality. Instead, make sure that enough code quality work is...