Please help Should and transplant or not

I got 2 plants in pots i want to put in ground before they flower one is in a 5g pot i think its 3 feet+ and other is probably 10g its been lst. im building 2 planters that i want to put them in so they can go straight down into the earth and im hopping they will grow bigger and better. I transplanted 2 times before last time was a couple months ago do u think i should do it or not risk it please give me some advice to ease my thoughts

are they root bound? if not then no if yes then as long as they havent started to flower then go ahead

i wouldn't do it unless you think the plant is rootbound especially if your gonna put them in the ground soon anyway save them the stress and just put them straight in the ground. i have 3 in a greenhouse and they were in 3gal pots after a month or so they started getting pretty large i started them indoors and they were drying out fast so i just put them straight in the ground and they're alot happier now for it and i'm in the uk where the weathers been quite shitty this summer

im not sure if they are rootbound but one put is medium size and i expect them to get huge during flower