I'd like to experiement & learn with RPi with SSD or HDD. When I get my RPi I'll run bitcoin node SSD 24/7.
This is not true, you can set the bootloader of a current RPi 4B to boot from other attached storage devices than the microSD card. A Compute Module 4 can even boot directly from an attached NVMe SSD card if it's on a board that exposed the Compute Module 4's PCIe lane to a NVMe slot.
One of my RPis doesn't even have a microSD card inserted, it boots straight from an attached USB3-SATA enclosure with a HDD in it. It runs a headless Raspbian OS 64bit no-GUI with a simplified Raspibolt installation, basically only Bitcoin Core. No wear'n'tear of a poor microSD card.
I could've used a SSD instead of the HDD drive, but I had no spare 1TB or more SSD for it. For this RPi node I don't need an I/O monster, runs just fine with the HDD (I copied the blockchain data off one of my other SSD nodes).