This is a mainly esthetic decision, as the swim platform's width doesn't affect the performance of the bracket in any mayor way. We love gunwale to gunwale, full width swim platforms, as we personally feel they tend to tie together the back of most boats just right, but that's us. A wider swim platform affords a bigger stage on which to fight and load in a feisty big catch, or more space to check on an outboard from the deck, or to lay tools/spares when doing maintenance on the engines ashore. The wider the platform, the costlier the bracket though, as that's one of the major cost driving choices.