A tiered storage space or cache for a mechanical drive is what I do with those these days

you will want to make sure that its firmware is up to date first as those models had a problem with reading and need periodic conditioning in newer firmware before you put it to use!
Yes -- definitely a use for a dedicated, undersized SATA SSD. Get your 1 or 2TB HDD -- bigger as you might prefer -- and install them. If desired, put the OS on the HDD -- otherwise, all the file collections of different usages or size range.
Get your OS and system all tuned up so it makes you feel proud. IF you want to spend some money, find a matching set of 16GB or otherwise increase the size of your memory as you're inclined or not to pay. People using a 16GB kit might be able to allocate 4 to 6GB for caching.
But with or without the extra RAM, you could optionally spend ~$30 on Romex PrimoCache 3.02. And before you do that, you'd have a 60-day trial period. There's a forum and tech support interacting with the forum.
If you have a reliable UPS powering your PC, you can enable deferred writes, which will then blow away the benchies for the standalone storage device Random Writes benchie. You can "Restore existing cache to RAM" from a Restart or fresh boot, and have it take effect immediately "On Windows bootup" or upon desktop display. you can define separate read and write caches for a particular HDD on the SSD. Basically, while you might only use the SSD-caching feature, with enough RAM you could have two-tiered caching. The Primo 3.02 version seems to make all of these things work quite well.
But I would use a 128GB SSD for caching if I didn't have a system allowing me to use a 250GB NVME M.2 PCI-E x4 for caching. I've really been doing disk caching since the Z68 chipset and ISRT in IRST. The proprietary options in Intel SRT, Marvell Hyper-Duo, or even Samsung's RAPID for caching an SATA SSD to RAM -- don't allow you to do some combinations of devices and caching, have conflicting configuration requirements, and are unnecessary in my opinion when compared to the software option of PrimoCache. This latter alternative as "lifetime license per machine" is agnostic to hardware, RAID or AHCI configurations. I can use it to cache a RAID on a Marvell controller to a device on the Intel controller. And I don't remember a piece of software so reliable or recoverable.