Don't know if DLR is this way still, but WDW no longer requires cancelling a park reservations to schedule a new one. You can modify all park reservations now.
At WDW you can purchase G+ & book your first ride before you leave your on site hotel. At DL last month we couldn’t start booking LL until after we’d made it through the hoards & entered the parks. DL’s ‘early entry’ for resort guests (we were at the GCH) was…unpleasant…they let everyone in & ‘hold’ the non on site people on Main Street, I guess so they can start making their LLs? It made trying to take advantage of early entry a very negative experience IMO.
Well I'm happy to hear this as I'm headed to WDW in 23, but yes these 2 roadblocks still exist at DLR. Hopefully they get removed.