KDE Neon: Staying on the Ubuntu LTS Base vs Chasing the Latest Plasma Repo

On a single KDE Neon machine I want to decide between two documented approaches: keeping the Ubuntu LTS base as the stable core with apt pinning preferring base packages, versus leaning harder on the KDE Neon user repository for the newest Plasma and KDE apps. The constraint is one machine that must balance security update cadence against feature freshness.

The documented dual-repository model uses pinning so Ubuntu base packages win over Neon user packages. That split is predictable but version-sensitive: pinning priorities and repository contents can change between releases, so behavior on one base may differ from another and would need to be checked on the installed release (e.g., with apt-cache policy on a Plasma package).

There is also the longer-term question of the base itself. The documented guidance leans toward a clean install when moving from one Ubuntu LTS base to the next, rather than an automated in-place upgrade.

Questions:

1. Is staying strictly on the LTS base with default pinning the safer choice for update cadence, or does the Neon user repo keep pace with Plasma security fixes well enough to justify freshness?
2. When the current LTS base nears end of life, is a clean install genuinely preferable to attempting an in-place base migration?
3. What is the risk of third-party PPAs overriding the pinning assumptions and causing unsupported partial upgrades?