NOOBS installation size idea - modularize!

[procount]

The distros used with NOOBS are getting so large that it is difficult to fit them all onto a 4GB SD card.
NOOBS v1.3.10 has therefore removed all but Raspbian, with the remainder having to be downloaded "on the fly", so it is now closer in function to NOOBS-lite.
Here is an alternative suggestion to harmonise the installation process so that it is suitable for different sizes of SD card or installation preferences.

1. Make NOOBS-lite the primary release of NOOBS. i.e. just the installer with no included OSs. User can unzip this file to a blank FAT32 SD card as now. User could use this as is and download/install any OS from within NOOBS as now.
2. Make each OS to be installed by NOOBS available on the website in a NOOBS installable format. i.e. as .tar.xz files, complete with all the installation slides, .json files etc. and package them up into a zip file for each distro.
3. User can download the zip file(s) for whichever OS distros they want to install and unzip them over the top of their NOOBS-lite installer on the SD card. User could now use this SD card to install those OS to a PI when not connected to a network. If connected to the internet, NOOBS lite could additionally offer the other OS available for download as now.
4. Modify NOOBS to look for OSs on /dev/sda1 in addition to /dev/mmcblk0p1 and the internet. In this way a user can have a minimal NOOBS image on their SD card, with more available space on it for their Distros. They can keep all their OS installation files on a separate USB flash drive, to be plugged in just when they want to re-install. In this way they can still do a recovery option when away from the Internet.

Of course, steps 1-3 could be done by an average user now, but packaging the distros as a zip file and making them available on the website for download would make it easier for newbies to select and download.
Step 4 needs a modification to NOOBS, but I think it would bring a lot of flexibility without overcomplicating the installation.

[procount]

Some benefits for NOOBS additionally searching /dev/sda1/os for installation files as point 4 above:

1. More of the precious space on a 4GB SD card can be used for the installed OSs because less space is "wasted(?)" to host the OS installation files in the NOOBS recovery partition.
2. In the event of a problem, the OSs can still be reinstalled after inserting the USB recovery drive with the OSs on.
3. Only 1 USB drive is needed with the OS packages on, so if a user has many RPis, the OS packages don't need to be hosted on each SD card.
4. It still allows the user to recover the OS when there is no internet connection (important at Raspberry Jams, and school clubs etc)
5. It saves internet download bandwidth. Not everyone has unlimited broadband so re-downloading the OS for each install could be costly for some people.

[Ruffio]

@procount is this still an issue?

[procount]

Partially solved by @robbi5, but it would be nice to allow users to download a zip or tar file for each distro so they can choose which to download and integrate into Noobs-lite.

[procount]

A similar download feature has been added to PINN.