Prevent chainloading by grub after rEFind
Solution 1:
There is a distinction between a boot manager and boot loader.
From the official website of rEFInd:
rEFInd is a boot manager, meaning that it presents a menu of options to the user when the computer first starts up [...]. rEFInd is not a boot loader, which is a program that loads an OS kernel and hands off control to it.
but GRUB is both:
Many popular boot managers, such as the Grand Unified Bootloader (GRUB), are also boot loaders, which can blur the distinction in many users' minds.
If you want to remove the timeout in the GRUB boot menu you can edit /etc/default/grub
and set
GRUB_TIMEOUT=-1
You then have to do
sudo update-grub