Akismet does not check message field

Hello,
Thanks for the very useful plugin!
This is the source code for the form in the question:

<label> Your Name (required)
    [text* customer-name akismet:author maxlength:80] </label>

<label> Your Email (required)
    [email* customer-email akismet:author_email maxlength:80] </label>

<label> Subject
    [select* subject-menu "Refund Request" "Privacy Concern" "Terms Question" "Other"] </label>

<p style="margin-bottom: 0;"><label style="margin-bottom: 0;"> Your Message (optional) </label></p>
<p style="margin-bottom: 0;"> [textarea customer-message maxlength:1000] </p>

<p style="float: right;"><span> [count customer-message] </span> / <span> 1000 </span></p>

<p style="clear: both;"> [submit "Send"] </p>

I test it in Chrome (Incognito mode).

Test 1:
The contact form is used.
1. Message is sent for the name = Alex, email = [email protected], message = a link from real spam
2. Message is sent for the name = Alex, email = [email protected], message = complex text containing a link from real spam
3. Message is sent for the name = Alex, email = [email protected], message = akismet-guaranteed-spam
4. Akismet catches the name = a link from real spam, email = [email protected], empty message
(I see the last case in Flamingo.)

Test 2:
WordPress comment form on this site is used.
1. Akismet catches the name = Alex, email = [email protected], message = a link from real spam
2. Akismet catches the name = Alex, email = [email protected], message = complex text containing a link from real spam
3. Akismet catches the name = Alex, email = [email protected], message = akismet-guaranteed-spam
4. Akismet catches the name = a link from real spam, email = [email protected], message = test
(I see it in the history of each caught spam comment).

Solution:
I solved(?) the problem with setting akismet:author for the message field:
<p style="margin-bottom: 0;"> [textarea customer-message akismet:author maxlength:1000] </p>

As the result, Test 3:
The contact form is used.
1. Akismet catches the name = Alex, email = [email protected], message = a link from real spam
2. Akismet catches the name = Alex, email = [email protected], message = complex text containing a link from real spam
3. Message is sent for the name = Alex, email = [email protected], message = akismet-guaranteed-spam
4. Akismet catches the name = a link from real spam, email = [email protected], empty message
As you can see, the cases 1, 2 improved in comparison with Test 1.

Please confirm if this solution is decent.
Are there other solutions?

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