Sometimes (no, often) I have trouble remembering kun readings like "kuba(ru)" (distribute) vs. "kabu" (share of stock) and I was thinking of using the RTK2 method of assigning visual elements to the kana and making up stories to remember the kun readings.

But after finishing RTK1 I'm not sure I feel like going to all that trouble.

Has anyone tried the RTK2 method of learning kun readings? Are there stories recorded somewhere?

Or is the only practical way just good old rote memorization (which I am NOT good at)?

SRS has its limitations, but for things like this it's unbeatable.

For example, currently active cards for 配 = くば:

Core6k:
会議で書類を配った。
会議で書類のコピーを配った。
チーム全員に名札が配られました。

Core10k:
被害者に救援物資が配られた
街で散らしを配っている
彼女はいつでも回りの人たちへの気配りを忘れない
彼は駅前でビラを配った

Harry Potter deck:
少年は新聞を配って歩いた
互いに目配せした

Self-made deck (from Yotsubato)
挨拶で配る粗品とか用意してるか？

if you read a manga with furigana that uses a ton of kanji you will be able to pick it up reasonably quick. kun yomi isn'T so bad, but SRS/straight up memorization helps in tandem with reading. I suggest reading one piece, because it uses a ton of kanji, not just joyo ones either, and it has furigana on all of them. sometime the furigana is "wrong" due to how characters talk, but overall its an amazing reinforcement of studying the kun yomis.