This can be loaded into Falkon but apparently it doesn't work. Why? (Based on https://letsblock.it/filters/youtube-shorts.)

shorts.txt

[Adblock Plus 2.0]
! Version: 202210181525
! Title: YouTube Shorts
! 
! -----------------------YouTube Shorts blocking filters-----------------------!
www.youtube.com##ytd-guide-renderer a.yt-simple-endpoint[title="Shorts"]:upward(ytd-guide-entry-renderer)
www.youtube.com##ytd-mini-guide-renderer a.yt-simple-endpoint[title="Shorts"]:upward(ytd-mini-guide-entry-renderer)
www.youtube.com##ytd-browse #dismissible ytd-rich-grid-slim-media[is-short]:upward(ytd-rich-section-renderer)
www.youtube.com##ytd-browse ytd-grid-video-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer:has-text(/\s(0:\d\d|1:0\d)\s/))
www.youtube.com##ytd-browse ytd-rich-item-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer:has-text(/\s(0:\d\d|1:0\d)\s/))
www.youtube.com##ytd-search ytd-video-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer:has-text(/\s(0:\d\d|1:0\d)\s/))
www.youtube.com##ytd-watch-next-secondary-results-renderer ytd-compact-video-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer:has-text(/\s(0:\d\d|1:0\d)\s/))
www.youtube.com##ytd-browse ytd-grid-video-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer[aria-label="Shorts"])
www.youtube.com##ytd-browse ytd-rich-item-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer[aria-label="Shorts"])
www.youtube.com##ytd-search ytd-video-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer[aria-label="Shorts"])
www.youtube.com##ytd-watch-next-secondary-results-renderer ytd-compact-video-renderer:has(span.ytd-thumbnail-overlay-time-status-renderer[aria-label="Shorts"])
www.youtube.com##ytd-browse[page-subtype="subscriptions"] ytd-video-renderer span.ytd-thumbnail-overlay-time-status-renderer[aria-label="Shorts"]:upward(ytd-item-section-renderer)
m.youtube.com##ytm-reel-shelf-renderer
m.youtube.com##ytm-pivot-bar-renderer div.pivot-shorts:upward(ytm-pivot-bar-item-renderer)
m.youtube.com##ytm-browse ytm-rich-item-renderer:has(ytm-thumbnail-overlay-time-status-renderer span:has-text(/^(0:\d\d|1:0\d)$/))
m.youtube.com##ytm-browse ytm-item-section-renderer ytm-video-with-context-renderer:has(ytm-thumbnail-overlay-time-status-renderer[data-style="SHORTS"])
m.youtube.com##ytm-browse ytm-item-section-renderer ytm-compact-video-renderer:has(ytm-thumbnail-overlay-time-status-renderer[data-style="SHORTS"])
m.youtube.com##ytm-search ytm-compact-video-renderer:has(ytm-thumbnail-overlay-time-status-renderer[data-style="SHORTS"])
m.youtube.com##ytm-single-column-watch-next-results-renderer ytm-video-with-context-renderer:has(ytm-thumbnail-overlay-time-status-renderer span:has-text(/^(0:\d\d|1:0\d)$/))

Hi, this one works nicely for feeds, maybe it could reduce the amount of rules you have here, the":upwards()" works nicely in uBlock origin

! Block shorts from feeds
www.youtube.com##yt-icon.ytd-thumbnail-overlay-time-status-renderer.style-scope:not([hidden]):upward(6)

Small nit: you have a type in your title. It should be "Youtube Shorts", not "Youtube SHorts" 😉