But clearly this encouragement to include automated tests is not enough
for some SRFI authors, who release their SRFIs either without automated
tests or with incomplete tests.
Automated tests are required for every SRFI when they are at all practical, which is almost always the case.
However, note that the requirement to include unit tests was only
added in May, 2018, so earlier SRFIs are less likely to have them. Perhaps you've been porting earlier SRFIs.
In any case, thank you very much for your porting efforts. Also, improvements to the tests are always welcome.