systemd path unit questions - eviltoast

Hello together. I try to use a systemd path unit, to monitor a directory structure. But as of now, I was only successful for the top level directory. The unit should be triggered, if a new file is written to either the top level of the monitored directory and also, if there is a new file in any of its subdirectories. I don’t know how to do that. Any ideas?

Additionally, the triggered service unit should be delayed for some time. Background is, that I automatically upload sometimes more than one file in a batch. So I will give the script triggered by the service unit the chance, to wait until the upload of all files is finished, so that I can work with all the new files with one script call, instead of multiple calls for every file. Is that possible?