Thunderbird as an "RSS" reader

[天王寺屋]

My main tool on the Web is an "RSS" reader.
RSS subscriptions are available in Thunderbird, but ....
Issue 1:
A few cases of no feeds that were available for subscription so far as version 91.x and are no longer obtainable starting with 102.x.
Issue 2:
Starting with 102.x, the folder tree structure (subfolders) is broken and subfolders cannot be created, and moved.
Issue 3:
It is no longer possible to "import into Thunderbird a list of feed URLs exported in OPML format from another feed reader, etc.".
I would like to see it improved, and furthermore, to achieve the same functionality as the desktop application "RSS Guard".
https://github.com/martinrotter/rssguard#readme

[Jon]

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