Thank you @DannyS712. But I still think that the option "excludezero" would be useful for all users.
I hope that it could be easy to create this option in MediaWiki.

In T215725#4952651, @Tgr wrote:

In T215725#4950163, @NicoScribe wrote:

But some people have no account on 'metawiki', for instance Hubert0482 and RalfU690717.

Yeah, bugs happen and might break local account autocreation temporarily. Also different wikis have different blacklists / abuse filters and those can block local account autocreation as well.

OK, thank you. I am just saying that it is not difficult to find other global accounts without account on 'metawiki': Bill Dance 22, Diane Sims Black, IanDBeacon 3, Larissa Cordova... Perhaps another Phabricator task should be created to investigate the bugs / blacklists / abuse filters, that are preventing these local account autocreations on 'metawiki'.
(And there are also old global accounts with recent activity but without account on 'mediawikiwiki + metawiki': Fear3235, James265, Saphomicron.)

It seems that you consider that a local account on 'metawiki' is autocreated, when a global account is created.
But some people have no account on 'metawiki', for instance Hubert0482 and RalfU690717.

I am sorry, but I think that the community does not know about the possibility to thank for flow-lock-topic and flow-restore-topic. And I think that the reasoning "I want to thank Foo for resolving this topic... No 'thank link' is displayed in the topic... No 'thank link' is displayed in the topic's history... I have to search for a 'thank link' in the public logs..." is too long (and complicated) for the contributors.
So I think that the 'thank link' should be displayed in the topic's history.

In this example, I was unable to thank for the edit of a topic summary of a structured discussion. I do not see the associated log type in the description of this task.

In T60485#2249703, @MGChecker wrote:

My preferred use case would be thanking file uploads. Furthermore, I would like to use it to thank sysops if I ask them to use their rights to do something for me, so deletion, rights and protect log would be nice options too.
If I think about ist, maybe thanks for blocks should only be an option since a block is a really destrucitve action. I imagine really weird situations about users thaning sysops because they blocked another user thex don't like...

What "weird situations" are you supposing?
Let's suppose that Foo and Bar hate each other, and each one has a "fan club of contributors", and Foo opens a request against Bar, and the sysop Baz blocks Bar due to the request. What kind of harassment/trolling (in the block log) are you supposing? The "Foo hooligans" would thank Baz in the block log? The "Bar hooligans" would dishonestly thank Baz in the block log?

In T60485#2249703, @MGChecker wrote:

My preferred use case would be thanking file uploads. Furthermore, I would like to use it to thank sysops if I ask them to use their rights to do something for me, so deletion, rights and protect log would be nice options too.
If I think about ist, maybe thanks for blocks should only be an option since a block is a really destrucitve action. I imagine really weird situations about users thaning sysops because they blocked another user thex don't like...

I do not understand the hesitations about the log type "block" (and "gblblock" and "gblrights" and "globalauth").
A block can be seen as a "destructive action". But a deletion can be seen as a "destructive action" too. And these two actions can also be seen as "positive actions", because they protect the Wikimedia projects.
I suppose that the hesitations should be about consensual/contentious actions, instead of positive/destructive actions. But all the actions can be considered contentious (by some users): there are contentious blocks, contentious deletions, contentious moves, contentious protections, etc.
I think that most of the actions are not contentious, and that most of the contentious actions do not lead to harassment/trolling, and that the sysops have the necessary experience to handle these situations. So I think that we should assume good faith (of the contributors who just want to thank the sysops) and allow 'thanks' for the log type "block" (and "gblblock" and "gblrights" and "globalauth").

I understand the reasoning to disallow 'thanks' for some logs (such as User creation log and Thanks log, because it can be confusing). But I see no reasoning to disallow 'thanks' for these log types:

• abusefilter
• gblrename
• renameuser
• stable (for the pending changes log).

There is the same problem on Wikipedia in Italian, cf. https://meta.wikimedia.org/wiki/Talk:Community_Tech/Ping_users_from_the_edit_summary#Reverts_to_last_edit_by_XXX
There is the same problem on Wikidata: I have been notified for the edit https://www.wikidata.org/w/index.php?title=Q1420&oldid=prev&diff=650083501