What lesson did he learn?

Question

Kevin is a vegan. But not the good kind of vegan. The kind that insists everyone in his neighborhood needs to stop cooking meat at dinner time so he can run outside. Kevin pushed everyone around him so hard, even his vegan friends found it annoying. Now he feels alone. While eating his 2nd kale salad of the day, Kevin wrote a poem. He hid the lesson he learned within it. What's the lesson he wants to share with PSE?

He
alone
societally

will
evoke
alienism.

And
randomly,
seemingly,
reproduce.

Those
placebos
likened to
sensitivity.

Even
scolders
invite
bravoes
silently.

Hint 1:

The line breaks are intentional, as are "."

Hint 2:

This one may be early, so keeping it simple: keep the tags in mind

Hint 3:

Up to one letter of the solution can be found per line

Hint 4:

There was an original draft, containing the same hidden message/following the same pattern.
He
alone
societally,
adversatively
insociable.

will
randomly,
seemingly,
reproduce.
[...] No changes to the rest

Hint 5:

After a few days, Kevin was able to make amends with his friends. He wrote another little poem, using the same cipher, just to give everyone at PSE a fifth hint.

Look
ahead
resited,
instance
rectified.

Forgive
gaffs
like a flash,
persevere
blithely.

Hint 6:

The poem is written by the cipher. As in, you don't start with a known work or other poem but start with your message to encode, and build around that. (It's not an efficient cipher in that sense). It may be possible to accomplish with known works, but highly unlikely.

Hint 7:

A line following a blank line must contain 0 letters of the solution, and are the only lines(other than blank) that don't contribute to the solution.

Answer 1

Update - Thanks to @hagfy, the pattern has emereged.

The final message is:

LIVE AND LET LIVE

Which fits the story quite nicely.

The message can be extracted from the cipher poem as below:

The line of each section has a letter of the answer at a particular index. The full-stops indicate word breaks.

How to know which index to chose?

Originally I thought that the first line after a line break somehow contained some cipher metadata which identified the indexes to choose. However, this was misguided.

With some guiding light from @hagfy, the way to select the index is to take the number of syllables from the previous line and multiple them by two, and use the result as the index. He - 1 syllable, next index = 2 alone L - index 2 - 2 syllables, next index = 4 societally I - index 4 - 5 syllables, next index = 10 will - 1 syllable, next index = 2 evoke V - index 2 - 2 syllables, next index = 4 alienism. E - index 4 - 5 syllables, next index = 10 And - 1 syllable, next index = 2 randomly, A - index 2 - 3 syllables, next index = 6 seemingly, N - index 6 - 3 syllables, next index = 6 reproduce. D - index 6 - 3 syllables, next index = 6 Those - 1 syllable, next index = 2 placebos L - index 2 - 3 syllables, next index = 6 likened to E - index 6 - 3 syllables, next index = 6 sensitivity. T - index 6 - 5 syllables, next index = 10 Even - 2 syllables, next index = 4 scolders L - index 4 - 2 syllables, next index = 4 invite I - index 4 - 2 syllables, next index = 4 bravoes V - index 4 - 2 syllables, next index = 4 silently. E - index 4 - 2 syllables, next index = 4
Because blank lines obviously have no syllables, any lines following a blank cannot contribute a letter to the solution, as index of zero is empty.

Regarding a couple of the hints:

Hint 4

Spells the same thing, but without splitting "LIVE" across sections:
He alone L - index 2 societally, I - index 4 adversatively V - index 10 insociable. E - index 10 will randomly, A - index 2 seemingly, N - index 6 reproduce. D - index 6

Hint 5:

Literally spells out HINT FIVE
Look ahead H - index 2 resited, I - index 4 instance N - index 6 rectified. T - index 4 Forgive gaffs F - index 4 like a flash, I - index 2 persevere V - index 6 blithely. E - index 6