I'm looking to safely upgrade the Archer VR900 v3 firmware to the latest stable version.

I have specifically the following:-
Hardware version: Archer VR900 v3 00000000
with
Firmware version: 0.2.0 0.9.1 v0069.0 Build 170303 Rel.59897n
currently installed.

Following the VR900 router user manual:
https://static.tp-link.com/1910012121_ArcherVR900(EU)(AU)_V3_UG.pdf
on page 98, I checked for a firmware update (click on the 'Check for Upgrades' button) that produced the message 'Your firmware is up to date'.

I then went to the VR900 support webpage:
https://www.tp-link.com/uk/support/download/archer-vr900/#Firmware
and discovered two updates since build 170303 (2017-03-03) currently installed in the router.

The updates were:

Firmware Archer VR900(EU)_V3_200228 (2020-03-17 - 'Bug fix of CWMP vulnerability.')

Firmware Archer VR900(EU)_V3_210322 (2020-06-28 Beta - 'This beta firmware has enhanced the performance and it's recommended to upgrade to this firmware for a better experience.')

My questions:

1. Are both these upgrades suitable for my router model (Archer VR900 v3 00000000) (I'm in the UK)?

2. How come the current router software (170303) is not finding the latest upgrades?

3. If the updates are suitable, is firmware 210322 stable enough to use given it's labeled as beta however dated 2020-06-28 so I guess that would mean enough time to test the software and come off beta?  Is the beta version stable?
For those non-technical reading, the term 'Beta', refers to a temporary software development phase when the software (firmware) is feature complete but likely to contain a number of known or unknown bugs.

Browser screenshot of the router software:

Web browser screenshot of the VR900 router software download webpage (June 2021):

https://www.tp-link.com/uk/support/download/archer-vr900/#Firmware