can any one give me any advice on lst topping and ...

So essentially you wanna do all the training you can before you get to flower . You dont really wanna do any training in flower other then some LST or maybe light defoliation in order to keep the stress level's as low as possible . For topping I would recommend that you top from the 5th node and up on a photoperiod plant . I say this because you want the tap root of your plant to develop and grow to a good length before topping . Once you top it stunts the steroid that makes your plant grow tall and makes it grow more bushy . With that being said the growth of the tap root is also stunted , so topping a plant to soon can result in a slow growing plant that will likely remain smaller then the rest for the duration of the grow . If you do it from the 5th node and up your tap root is long enough that the recovery time of the plant being topped will be shortened as well as the side roots will explode in growth . FIMMING can be done from the 4th node because you arent removing the steroid that would push the plant to grow tall instead your just slowing its growth allowing for the rest of the canopy to catch up as well as promote new branches from were you have FIMMED . Once you have done either of these techniques I would give the plant about 10 days to recover before you decide if your going to either let it veg more or put them into flower . Over all your in good shape and its looking like that scrog will fill out nicely ! I hope this information serves you well in understanding what sort of training you can do during flower and what sort of training should be done during veg . -Happy Growing!!

Your plants look large enough to top at any time. Where you top depends on how small you are trying to keep the plant. I typically top down the 3rd node to keep my plants nice and short. Once you have topped the plant let it recover and grow a little bit and then either tie everything down to level out the canopy or strip all the growth below the top node and tie the top nodes growth down to start a mainline.

you've done a bang up job so far so congrats on that. your plants are ready to top anywhere below the first row of leaves and the second row. simple as that ! good luck ! hope this helps ! 🚀

I post a link for each method in the comment section but every links are coming from the website GrowWeedEasy, you will find plenty of tutorial/info there as there are many thinks to tell about these method 😊