The maximum number of Mist Edge devices supported for high availability is two. This ensures that there is a backup device in place to take over in case the primary device fails, providing redundancy and maintaining network stability.
Reference:
Mist Edge Configuration Guide
Juniper Networks Mist Edge FAQs

For Marvis, Mist AI's virtual network assistant, to provide a visualization of low coverage and low-capacity issues within the network, a floor plan is required. This enables Marvis to map the coverage and capacity data to specific locations within the physical space, allowing for precise identification and troubleshooting of network issues.
Reference:
Juniper Mist AI Documentation
Marvis Actions

The "Exceeded" status for a subscription means that the allowed usage defined within the subscription has been surpassed.
This typically refers to exceeding limits such as the number of devices, data usage, or other metrics specified in the subscription plan.
Exceeding these limits may require action such as upgrading the subscription plan to accommodate the additional usage.

Claim Codes: Claim codes are unique to each AP and can be used to claim only one AP at a time. This ensures each device is correctly registered and managed individually within the Mist system.
Activation Codes: Activation codes can be used to claim multiple APs at once, facilitating bulk onboarding and simplifying the setup process for large deployments.
Reference:
Juniper Mist Claim and Activation Codes
Mist Setup Guide

This method leverages data from access points to create a probabilistic model of where clients are likely to be based on their signal strengths.