Not really Edouard. WeatherCat will allow a resource to be out of date by up to one minute. So lets suppose your main custom web processing runs, everything will be generated and sent for upload. 2 minutes later you process the all_tags file - all resources required by the tags will be generated and uploaded again.
If however the tag file is processed within a minute of the resources being generated, then the resources won't be generated or uploaded again - it'll just use the ones generated and uploaded previously.
This does not apply to all resources however; custom graphs are currently generated and uploaded whenever the relevant tag is processed as are webcam tags (exception being the time-lapse movie - this is upload just once on the first run past the hour (assuming a movie$ tag was processed)).
It's an ongoing challenge I face to be able to determine what and when should be generated and uploaded.
Luckily WeatherCat's status window allows you to see easily how much stuff you've uploaded. We'll see that improve in the future to maintain monthly & weekly totals.
Cheers,
Stu.