Hey there,
We are working on it now, it is meant to be in the next release, it was removed because it was causing bugs in the way it was originally implemented, you are free to use the prior version 5.0.x if it doesn’t have other issues for your workflow, but it has been improved on in other ways since 5.1.x
The newer version of loop decay will also work more as people expected it to, the loop decay will enact automatically at every revolution of the loop during an overdub not only when a new layer is started
Thanks for the question