We use
DAS for my almost 5 year old. Obviously, he is height restricted on a lot of things. Or was the first time we went, now he's good for most, but still isn't interested in things like Space Mountain, Rock N Roller Coaster, etc. However, I also have teenagers who love the thrill rides. We ended up buying Genie + for MK and HS (I don't think it's worth it for EPCOT or AK) and using that in conjunction with DAS, particularly on the rides where my little guy wouldn't/couldn't ride. In these instances, we used Rider Swap when available. If it was at the beginning of our return window, we sent the teenagers ahead to ride first, and hung out nearby entertaining the little one (usually with ice cream or popcorn), then swapped when they were done. If it was near the end of our return window or it was a particularly long LL line and we weren't certain we could all ride before the expiration, we approached the blue umbrella as a family to notify them of intention to use Rider Swap, they did something on their screens with our magic bands, and then we sent the teenagers through and we rode when they were done. Very easy.
In the rare instance where we didn't have either a
Genie+ or DAS return time for a ride and my little guy didn't intend to ride it, we had to make a judgment call on whether to have him wait in line with us. If you're doing standby, I think everyone is supposed to wait in line the first time, and the swap occurs (or return time is issued) at or near boarding. When our guy was not capable of waiting in the standby line, we approached the blue umbrella in advance, explained the issue, and like 4 out of 5 times, they issued us a return time without making him or the second riders physically wait in line. We didn't try this often, so I'm not sure whether that is standard or we were just lucky. We felt lucky and didn't question the few times we were told we had to wait, because we try not to take advantage. We are the type who don't request a DAS return time unless we really think our guy is going to need it (like, standby waits over 25-30 minutes). So we had him wait in standby lines for Rider Swap when lines were estimated at 30 minutes or less.