In winter most bonsai are dormant. Evergreens however remain active during the winter in periods that the tree is not frozen. As such, any energy dis-balance that is present in fall, is enhanced during winter. A good fall-thinning can help to re-balance your Juniper Bonsai apical dominance.
Why prune a Juniper bonsai in Fall?
How to prune a juniper in Fall?
How to encourage lower canopy dominance in Juniper bonsai
Did you know @XaviersBonsaiRetreat did a special breakfast session with me?
https://youtu.be/ngaoA9K-Eug?si=Ljau6VvIVwAZfUJl