You can save time when experimenting with delivery parameters by delivering the application in memory rather than saving it to disk.
If the deliver
keyword :in-memory-delivery
is non-nil, the delivered image is not saved to disk, but instead starts up automatically after the delivery operations are complete.
For example, a good early test is
(deliver 'user:run
"the-application"
0
:in-memory-delivery t)
Note: The image exits as soon as the application terminates.