I'm really not sure the following info will be of any value to you in terms of your overall objectives and my incomplete understanding of the equipment you're working with. But just in case the following might be of some interest given your situation and objectives here it is FWIW...
The mobile rack model for removable HDDs (& SSDs as well) we use virtually exclusively on every desktop PC we build is the...
Athena Power MR-125PB
https://www.newegg.com/Product/Product.aspx?Item=N82E16817995104
$17.10 + 5.16 = $22.26
This mobile rack is a two-piece affair - a removable tray and the rack itself which is affixed to the desktop PC's 5 1/4" bay (identical to affixing an optical drive or some such 5 1/4" device). This model contains a small fan that is dead silent in operation. The rack is dead-flush with the PC case's front bezel.
So you can install any number of these mobile racks as long as a vacant available 5 1/4" external bay is available in your desktop case.
One particular feature we like about this Athena mobile rack model is that it's equipped with an ON-OFF power switch button, a most desirable feature in our opinion. Assuming a user is working with multiple removable hard drives (or SSDs) in their mobile racks and/or has also installed a fixed internally-connected HDD/SSD in his/her system, it's a simple matter to press the ON-OFF button and "on-the-fly" temporarily disable one or more of the mobile rack's drives without the need of using the rack's lever to remove the rack's tray (caddy) containing the HDD or SSD from the rack's internal SATA power/data connectors.
Of course should the user choose to do so it's a relatively simple matter to press the removable tray's lever release button and thus physically disconnect the removable tray containing the disk drive from the system, thus disconnecting the rack's HDD/SSD SATA data/power connectors from the mobile rack's connectors. A simple pull of the tray's lever is all that is necessary.
And should a user desire to employ additional HDDs/SSDs, he or she can simply remove the present disk from the tray and plop a different one in. Thus, users have an UNLIMITED number of drives at their disposal with this device. A simple no-nonsense procedure that's accomplished from their computer chair.
So with a removable HDD/SSD, one gets the speed advantages of an internally-connected drive coupled with the absolute security of the backup/storage data on that disk by easily disconnecting/uninstalling the disk from the system whenever it's desired by the user. Again, all from the comfort of their computer chair.
The one negative to this particular mobile rack is that it's designed to house 3.5" drives and not 2.5" drives (SSD or HDD), however, for nearly 10 years now we've been installing SSDs (or 2.5" HDDs) in the rack without any significant problems. In the past we simply cut up a couple of foam pieces (the type of stuff you frequently get as packaging material) and butt the pieces against the 2.5" drive so that it's firmly situated in the rack. Seems to work fine.
Another alternative is to drill two small holes in the bottom of the rack so that they're oriented with the screw holes found on the bottom of the 2 1/2" disk. Then screw the drive to the rack. Works quite well as long as you can properly orient the drilled holes with the screw holes of the drive.
And I'm aware of other users who simply use packaging tape for this purpose.
Lately we've found that by using adhesive strips (Scotch brand & others) to the bottom (rear end) of the SSD (or to the tray itself) works just fine. And it has the added advantage of easily removing the SSD from the tray and inserting another SSD in the removable tray if & when the need arises.
Should the user be working with a 3.5" HDD all that is necessary is to "plop" the HDD in the removable tray. While screws are supplied to fasten the drive to the tray we virtually never use them unless we're transporting the HDD in its tray over some distance. The 3.5" HDD fits perfectly in the tray without being screwed down.
Over the years we've probably installed hundreds of these racks in the desktop PCs we've built and for other users. We've encountered very few problems with these racks and found no negative implications involving performance & longevity aspects between drives installed as removable drives and drives directly connected to the motherboard's SATA data & power connectors. While the rack & removable tray are fashioned from hard plastic they've held up quite well over the years. We've have encountered very few defective racks/trays and they're used quite extensively in our operations.
I can virtually assure you that once you begin working with one or more of these mobile racks that contain removable HDDs or SSDs you'll never want to build another desktop PC that's unequipped with one or more of these mobile racks. They're that good.
Again, I'm unsure whether the preceding is of any value to you given your specific equipment and objectives.