Keeping mother plant long term

Nice! Idk how much headroom you have but you should definitely keep her short. Toppings and LST. You’ll still want to defoliate by taking clones even if you don’t keep them. Maybe root one in soil so it’s not a daily task. And maybe only give it a little bit of light. Not enough to thrive, enough to stay alive, to slow her growth.

 

18 hours of light. Weak lighting like a light bulb for your house a led bulb
EcoSmart 60-Watt Equivalent A19 Non-Dimmable LED Light Bulb Daylight (8-Pack)-B7A19A60WUL38 - The Home Depot Something like this . 2 Of them will be perfect.
Keep topping it make the plant into many tops . I had a mother plant for almost a year before it got tired of me cutting on it .

 

I would just cut a clone make sure it roots and then just throw away the rest.. once said clone gets too big for your area cut a clone... make sure it roots and throw out the rest of the plant. Well I think you can get the picture, Its a continuous clone

 

Perpetually purple.

 

I maintain my moms using Bonsai methods. I’m not afraid to cut back a plant or bare root the thing to prune the roots.
I don’t recommend giving it weak light, I do recommend 1/4 strength nutrient to slow growth.

This photo shows a Blue Dream mom that’s 30 months old and has given many clones for my small grow. Trimming back the top and roots really help.

 

I get your concern about pruning roots. Your quest to is to maintain genetic material. You don’t need to root prune if you don’t want to. You can keep that plant until root binding kills it. That will take quite a while. In the mean time you can take nice clones til the cows come home. happy cloning!