...le cast and script

http://tvline.com/2018/05/10/big-bang-theory-recap-season-11-episode-24-sheldon-amy-wedding/

"Usually our scripts come in at about 40, 45 pages. This one was about 65 pages," says showrunner Steve Holland, who adds: "The trickiest part was juggling this big cast of characters. We had so many great people coming in and we had so many little story threads (to service)."

ALSO:

Holland discusses Sheldon's growth: "We've been trying to build to that all year" (https://www.hollywoodreporter.com/live-feed/big-bang-theory-season-11-finale-explained-sheldons-scientific-discovery-stephen-hawking-tribute-1109270)
Mayim Bialik: "For me, it felt a lot like a real wedding" (http://www.vulture.com/2018/05/the-big-bang-theorys-mayim-bialik-on-amys-wedding-dress.html)

...le cast and script

http://tvline.com/2018/05/10/big-bang-theory-recap-season-11-episode-24-sheldon-amy-wedding/

"Usually our scripts come in at about 40, 45 pages. This one was about 65 pages," says showrunner Steve Holland, who adds: "The trickiest part was juggling this big cast of characters. We had so many great people coming in and we had so many little story threads (to service)."

ALSO:

Holland discusses Sheldon's growth: "We've been trying to build to that all year" (https://www.hollywoodreporter.com/live-feed/big-bang-theory-season-11-finale-explained-sheldons-scientific-discovery-stephen-hawking-tribute-1109270)
Mayim Bialik: "For me, it felt a lot like a real wedding" (http://www.vulture.com/2018/05/the-big-bang-theorys-mayim-bialik-on-amys-wedding-dress.html)

They should have done an hour-long episode. I think we could have seen more of everyone that way. The episodes without commercials are 21 minutes long and they crammed a lot of story and characters into that show last night.