With few exceptions, most activities you would run in a love setting can be redesigned to work in a 4Door setting. Use your creativity and find a way-- then share with us.
It is ok to change the words and headings if you need. Feel free to call the Library the Resource Center, or the Playground the Game Center, etc. The names matter less than the principles of the format. For example, in one course, we collapsed all the Libraries from each module into one DATA CENTER. Each module was called a MISSION and contained CAFE, PLAYGROUND, and ASSESSMENT activities. We simply reorganized, but all the values of the format remained the same.
Align, align, align. Every item, every assessment, every activity must align with each other.
Never have extraneous stuff. If an item doesn't support meeting the objectives, don't have it. If an assessment doesn't support an objective, dump it.
Don't worry if participants skip parts of the course. As long as they pass the assessment, that should be all you care about as you evaluate success.
Foster engagement with you, between participants, and with other SMEs. Engagement is an excellent way to foster a motivated learner.
Keep your assessments job related and action oriented. Make participants do something specific to what they would do daily. Avoid multiple choice tests or other silly regurgitation exercises.
Try and keep the course to one month or less. Otherwise participants can get a bit lost (as will you).
The 4Door format is not time bound. Stakeholders will demand to know how long it will take participants to complete the program. This is not really predictable outside of range. The reason is tip #10.
Remember... this format is about participant autonomy. How a participants completes the course is not important-- just that they complete the final objectives.