We permit people to put up WIP builds and to share their progress with the community freely - people have been doing so in the dedicated channel on our Discord server, for example. If you want to post a WIP build, you can also update it before the submission deadline as you wish - the evaluation will be based on what we have before us after that deadline passes, after all.
Alternatively to posting on our discord, you can also put up a WIP build and then make devlog updates or, if you want to, do so in the discussions here.