uVisor ACLs, protecting a memory zone


My program has two boxes, the first one is the main and another one : box_test.
I want to use a memory zone in box_test, so i declare it the box ACLs, the thing is, i don’t want to declare this memory zone in the main ACL because if i do so, we can access this memory from any other new box. Is it possible to do so? I mean to have something like this for example:

#define MAIN_ACL(acl_list_name)                           \
  static const UvisorBoxAclItem acl_list_name[] = {     \
    {TMR2,                                  sizeof(*TMR2),    UVISOR_TACLDEF_PERIPH}, \
    {GCR,                                   sizeof(*GCR),     UVISOR_TACLDEF_PERIPH}, \

#define ACL_box_test(acl_list_name) \
    static const UvisorBoxAclItem acl_list_name[] = {   \
        {(void*) 0x20020000,       0x20000,                 UVISOR_TACLDEF_PERIPH}, \ // this is the zone i need to protect from all other boxes