Is it Possible to Use ‘Something Else’ to Resize Partitions?

[Mart]

I want to resize/shrink my root and home partitions to free up enough space at the end of my drive to install and dual boot a second Linux OS. Of course, I plan to keep Linux Lite as main driver. I’ve considered using Gparted but find it awkward at best and have read that applying a lot of changes in GParted can take a long time, in some cases a couple of hours or so. I don’t want to do a fresh install and resize my partitions that way because I want to keep my system’s customization. So the solution I'm going to ask about here might seem a bit crazy, but bear with me. I saw a video tutorial by quidsup​ called ‘How to use Partition Editor in Ubuntu Installer’ -here’s the link: https://www.youtube.com/watch?v=OU_dkeFprhY

In this YouTube video, quidsup re-installs Ubuntu, but more interestingly resizes his Windows ntfs partition but doesn't format it, so preserving it. So this got me thinking. To preserve an existing home partition (when doing a series install/upgrade in Linux Lite, for example) you would also leave the home partition unformatted to preserve it. So would it be possible to resize my root and home partitions using the ‘Something Else’ manual installer in the live Linux Lite usb, but leave them both unformatted in order to preserve them, and then proceed to click ‘install’ as required to complete the process (assigning grub to /dev/sda as normal). Would this destroy my OS, or instead preserve my customized OS with suitably resized partitions and new free space for my dual boot? Feedback please.