Time Capsule A1470 2.5" drive works, but possible issues?

Good day,

I have a Time Capsule 5th gen A1470 that was in storage for several years; the internal HDD had failed. Recently I decided to see if I could get it set up and running again to sell. I followed the iFixit guide, but decided to use a 2.5" 2TB Firecuda drive that I had from a laptop, and purchased an Orico 2.5" to 3.5" adapter for the smaller drive. The install went ok (I'm not a techie but have done similar work on the beloved older Mac Mini's and MacBooks and on my kids' laptops etc), and of course I had to trim out the rubber pads for a good fit. Reassembled everything and got it all set up using Airport Utility (my M2 Mini is running Ventura 13.6.7). Ran it for a few days, secure-erased the disk, etc. I also tried dragging and dropping media files onto the disk, which worked. The disk was recognized as available to be set up for a Time Machine backup, but I didn't go further, as the router is redundant in our home and I have other backups. So to me, it all seemed to be working ok. Subsequently I listed it for sale locally at what I think was a fair but negotiable price.

Someone saw the ad and contacted me, stating the following: "...it will burn out the 5V rail since it's running a smaller drive. The higher voltage rails are more robust for the larger drives."

After seeing that, I deleted the listing, at least until I have more information. I spent the last two hours searching up older posts and threads on this topic, here and on other Mac sites, and I found the following:

• The power supply could fail, though this was mostly stated about older-gen TC's, not necessarily the 5th gen.
• Don't use an SMR drive (which the Firecuda is)
• The 2.5" drive uses less power so should be ok (which seems to contradict the message I received).

Given the first two bullets, maybe I should forget about selling the thing and either use it at home, or remove the drive and use it in an enclosure and dispose of the TC. But I would appreciate insight into the claim that the 5V rail will burn out due to the smaller drive. Also, what is the issue with an SMR drive?

Thanks! :)