Edit: New version 30 september 2019 (4.1.2) : now is good, is improved with new features asked and bug fixes, like the sound and the easy delete shortcut to delete completed downloads, furthermore i see a whole new speed improvements. Thank you.
Now i think you have forgotten a feature: the "Empty the download files list (of downloaded files, green color) when the main window is closed" . ------------------
Old comment:
This is not good as 3.0.8 dta! version in seamonkey, this has limitations, the download window is worse ( WebExtensions limitations i guess ). This has fewer options and features. Try the 3.0.8 version of dta! in seamonkey browser (2.49.5 last version of seamonkey) , it 's the old and best dta! there .
In this new version (4.0.11 ) the download window uses the download system of firefox quantum , try to download many .jpg little/medium files together , 4 files per time, it is too slow and it takes too many resources until almost a browser crash! and has many slowdown even with a fast 4 core cpus and 16gb ram .... THe same situations when you try to cancel or remove all the downloaded files in the log window, i didn't saw an option to remove them automatically and it takes too many resources. there isn't a sound when the download completes either too .. I loved dta! for years but this is new version has many problems, if will not be resolved i 'll continue to use the old version in seamonkey. sorry