I would be careful letting them "grow as they please".

If your WW's are any like mine they will triple in height the first 3-4 weeks of 12/12.
I grew one FIMd and 4 "grow as you please" plants and the unFIMd ones took off like rockets. Seed grown WW's has to be kept on a leach indoors so at least keep it in mind before you switch them to 12/12.
I started to take action a bit late and had to get really rough with them to keep them from growing through the floor of my upstairs neighbour

Now I don't know what genetics your WWs are etc so it might not be as big of a problem with yours as with my Dutch Passion WWs, just keep a close eye on them and don't veg them more than 1/3 of the height you can take them in your cabinet if you are gonna grow them freely. And keep the lights as close to them as possible at all times. hehe.

Cheers
Puffzter