no, that is not done via developer mode. When You download or try to open an apk from any app, it asks you if you want to allow it to install apps and send you to the configuration dialog. You still have to validate the app installation manually tbrough another dialog. In that case I usually leave the config dialog open while the app is installed, then disable the app permission right after install because that option is usually not easy to find. I usually only do it once on a new smartphone to install f-droid from a browser then allow f-droid and aurora store permanently.

I think that is the part that should be fixed, users should be able to allow a one time exception to avoid letting that permission activated by mistake. I don't need to allow permanently a web browser to install apps.