and it’s all tightly wound In a big ball of clay.
all the more reason to
I reckon it's best to wait.
What would happen if I did chop and wire ... would I kill it?
You will lose all of 2021 as it sits around waiting for vigour to return.
Sure it is possible to kill it by reducing and wiring now, probably not though.
However if you attend to the roots in Spring after doing that now, well that certainly increases the chances of waisting all this time
working on it, photos, researching, asking in the forum, others time in responding, as well as a dead juniper.
You already have more than $10 tied up in it with time alone. Then there's wire, soil and a pot to be had. Food, water and a lot more time.
Here in zone 6 I've found early July heavy pruning is rewarded with junipers that are going into it vigorously.
Ok, I do the initial styling frequently 1st. For me it depends on what I have in front of me, and how the soil is draining.
I do this on a case by case basis. I do not do a lot of heavy pruning when I do this, but it IS faster to develop by attacking the roots 1st
with a full crown prior to the event. I normally reduce the root ball by maybe 60% initially, in height. Then I comb out the remaining roots
leaving original soil around the base, maybe even 20 or 25%. If it had more vigour than this one, I might even thin it some later in the Summer.
I'm done pruning my junipers for the year for the most part now anyway.
here ya go
I think practicing wiring everything that is there, to create an energy grabbing umbrella of foliage, will be the best use of your time currently.