The Poolte setup has always been difficult to maintain and update. Its develop has stagnated for a long time. Also the checks provide by the current version are not complete enough as issue8057 showed.
I think we should switch to Weblate which seems to be more active and provide a Docker image.
The structure of the translation repository should be changed to be compatible with weblate. I made a prototype here: http://hg.tryton.org/sandbox/weblate/. And so the scripts in tryton-tools should also be updated. By it is nothing too difficult. According to the documentation, it is possible to migrate the Pootle user to Weblate.
So I propose that the switch happens just after a release (e.g. 5.2) to ensure that we do not loose translation proposals.