On creative I found a new command that will help. But be aware this only works for the rank Bedrock and over. The command is /up and you type that then amount you wanna go up for example, /up 10. This will make you go up 10 blocks and place a glass block for you to stay at your wanted level. This is helpful for those who are tired of building up and breaking the tower, I mostly use this command for making the waiting boxes for roleplays and this can work on your friend's plot too. But you must be trusted on their plot and you can not use this command when your in a building because you can't go past the roof of the build. I hope I made your day's on creative much easier and good luck.
Hi there, Thanks for sharing this with the community. The /up command is actually a WorldEdit command which is why it is only granted to Bedrock+. I commonly use the command when making WorldEdit selections on my plot however, I can definitely see how it becomes useful when building structures in the sky. Have a wonderful rest of your day.