Up until Dynamics GP 2013 R2, there was both an Microsoft version along with an eOne version of SmartList Builder.
After GP 2013 R2, we gave the product back solely to eOne, so there's only their version from that point.
If upgrading from GP 8.0 to GP 18.4, I'm thinking you'd need to upgrade from 8.0 to GP 10.0 and then to GP 2013 R2 including upgrading SmartList Builder from within Dynamics GP, if using Microsoft's version.
Then once you get to GP 2013 R2, upgrading to GP 2016 and then GP 18.4, there will no longer be a 'SmartList Builder' feature to add to the GP installs, thus you'd treat SLB for GP 2016 and GP 18.4 like any other third-party product and upgrade those after upgrading Dynamics GP, contacting eOne for those upgrade steps.
Thanks