Have a question about my Rosa sinensis hibiscus that I brought inside a month ago. I've tried several times to over winter my big urns of hibiscus by allowing them to go dormant and bringing them back with poor results

This year I brought them in to grow in my veggie tent(I grow lettuces, greens and cherry tomatoes among other things, all straight hydro). They (1) had been fairly decimated by our local fearless deer, the other had only a smattering of buds probably due to our shortening days. Purchased from big home improvement store these been growing in 40% Ff ocean forest, 40% Happy frog, 20% perlite all summer

Tent is 78-80 F and 45-60 %rh Light cycle is 18/6 and probably not going to change much. Tent is pest and pesticide free. Water, oil, alcohol, and dawn mix and DE only IPM used. (Though I did douse them with neem the week before I brought them in.) Needless to say the sudden change from what was an October 12/12 photoperiod to 18/6 indoor has prompted a ridiculous number of blooms, they are quite confused!

The plan is to propagate them in a diy cloner with the prunings then return most to the yard in the spring. I will keep 6 (1 of each color) in the tent for experimentation) and to see how they do in hydro

My questions have to do with timing: The pruning, taking of cuttings? Not how, when. When do I up the nitrogen to build a nice bushy foliage base for going back outside, and will I need to adjust the light-day? What are my chances of building a franken-hibiscus...6 colors 1 bush? Is there any chance of using a hardy, or rose of Sharon rootstock? Sorry for the wall of text. Any advice from experienced growers welcomed.