What is this 100MB of data you are referring to - is it the squashfs image? This is already compressed so using zram to compress it again in RAM would not result in any significant benefit, and would in fact use more CPU to perform multiple rounds of uncompress/compress.
LibreELEC is designed to perform well within the memory constraints of the target device, eg. 1GB RAM on RPi3, which (on everything other than RPi0/RPi1) still leaves sufficient spare RAM to run a few background applications/services, so zram/zswap should not be necessary.
However if users choose to load the system to the point where all the available RAM is in use then that's not really a problem I think is worth solving with zram/zswap - the better solution is to partition your services on to dedicated/appropriate hardware so that LibreELEC as an HTPC client is running optimally (not having RAM/CPU intended for Kodi stolen by other background tasks) or continue using a single device but one with more physical RAM and/or faster CPU (4GB RPi4?)
Adding zram may mean more RAM appears to be available to applications, but it will also consume more CPU so what you gain on the one hand you lose on the other - you may have plenty of RAM available with zram but you may then experience stuttering during video playback as you are now CPU bound.
Planning on using any form of swap is a bad idea, particularly if your swap file is stored on SD card - it will be very slow, with or without zswap. Swap should only be used as a last resort.
There are several zram/zswap posts on the Raspberry Pi forum - this is probably one worth taking note of:
swap in Raspbian: More trouble than it is worth? - Raspberry Pi Forums
zram/zswap is a pretty niche requirement and not likely one that 99.99% of users will need. If you (or anyone else) wanted to test zram/zswap then the best option would be to enable the kernel configuration options and build your own custom/community LibreELEC: Compile [LibreELEC.wiki]
I am very inexperienced, I thought perhaps it may be useful to 'buy the developers' a few extra MB (50,100, 200?) to work with for room to move. Obviously you guys know your stuff very well. Wasn't sure if you had all heard of the technology at all.
Regardless I have faith, LibreElec has been wonderful on my R.Pi3, it was only a suggestion, thank you all for the hard work.