Both scripts working on Solus and Solyd with that tweak thank you!
I spent yesterday taking snapshots and installing and jotted down some tweaks you might want to use
Refractasnapshot line 242
text added "Please CLOSE any running applications NOW" to the top
$DIALOG --$QUESTION --title="Disk Space and Settings Report" --${BUTTON0}="Create Snapshot"${BUTTON0NUM} \
--${BUTTON1}="Exit"${BUTTON1NUM} --width 600 \
--text "Please CLOSE any running applications NOW
You will need plenty of free space. It is recommended that free space (Avail) in the partition that holds the work directory (probably \"/\") should be two times the total installed system size (Used).
-------------------------------------------------------
line 481
added width 200 as only "Refracta Snap" was displaying in the title
$DIALOG --$INFO --title="Refracta Snapshot" --width 200 --text="All finished!"
refractainstaller-gui line 229
height changed from 400 to 470 to show all the text without a scroll bar
# Select expert installation options
if [[ $install = "expert" ]]; then
opts=$(zenity --list --title="Installation Options" \
--text="Check the options you want for the installation" \
--checklist --column "Choose" --column "Num" --column "Option" \
--width=590 --height=470 \
---------------------------------------------------------
line 369
Changed title & text to mention Grub
Perhaps better to copy your Yad text into this script as you use Grub in that text
# Find hard drives, and choose one for grub
choose_grub () {
grub_dev=$(find /dev -mindepth 1 -maxdepth 1 -name "*[sh]d[a-z]" \
| sort | awk '{print "FALSE\n" $0 }' \
| zenity --list --title="Grub Bootloader" --text="Choose a drive to install the Grub bootloader or click OK without choosing a drive to skip this." \
--radiolist --multiple --column ' ' --column 'Hard Drives' --height=200)
----------------------------------------------------------
line 401
commented out the blkid terminal screen
# Show output of blkid for reference.
#xterm -fa monaco -fs 12 -geometry 90x20+0+0 -hold -e 'echo "Partition list (for reference.) You may need this later." && blkid' &
------------------------------------------------------------
line 668
added Please close etc.
zenity --question --title=Summary --ok-label="Proceed with the installation." --cancel-label="Exit" \
--text="Please CLOSE any running applications
while the installer is running.
Here is a summary of what will be done.
THIS IS YOUR LAST CHANCE TO EXIT before any changes are made to the disk.
$grub_dev_message
refractainstaller-yad
line 728
added Please CLOSE any
yad --info --title=Summary --button="Proceed with the installation.":0 --button="Exit":1 \
--text="Please CLOSE any running applications NOW!
Here is a summary of what will be done.
THIS IS YOUR LAST CHANCE TO EXIT before any changes are made to the disk.
$grub_dev_message
On both installers there's a 40 second gap between the
"Progress Copying file system" screen closing
and the "edit sudoers" screen opening.
is it possible to display a screen in the gap?
Please excuse an old man amusing himself

edit
I had to tweak this post a bit because I rushed it and made a few errors, I think it's right now