my expirenses wil never be exactly the same as anyone elses but the main thing about dream lenth that I have learned is that thinking ends lucid dreams pretty. fast when people told me to interact with my dream sourondings I never once thought that thinking alot could hurt this, but it might have. Im no expert but it helped me alot to realy kind of meditate in a way while I looked at my surroundings
hope this helps someone on the dreamscape!
Being someone that overthinks in waking life, my few successes in Lucid Dreams have been fairly thought-free, other than very basic ones of what to do, I've had almost no interaction with my environment other than say opening a window to fly out and punching through some doors in a cabin once!
I'm currently trying to drill in the reality checks to be instinctual which I guess is the holy grail for reality checking...but it's so hard!