The main advantage to execute the update commands in a post commit hook is to shorten the time the ZODB is locked. On disadvantage is that the transaction does not get roll-backed when the after commit hooks fail. This is of no concern here, as we anyway do not make the transaction fail when the updates in solr go wrong. So there is no real drawback of executing all the update commands in an after transaction hook.
The main advantage to execute the update commands in a post commit hook is to shorten the time the ZODB is locked. On disadvantage is that the transaction does not get roll-backed when the after commit hooks fail. This is of no concern here, as we anyway do not make the transaction fail when the updates in solr go wrong. So there is no real drawback of executing all the update commands in an after transaction hook.
For https://4teamwork.atlassian.net/browse/CA-4291