Issue with resuming large file downloads

So Firefox seem to run a file verify process on resumed downloads.

But on mechanical drive and a slower CPU this process can take up a long time with large download that is on near completion, effectively timed out the re-established connection that put on hold. This process loops itself indefinitely and ultimately end up with a stuck download unable to progress until given more CPU overclock and SSD to handle verification in time before the timeout.

Even with modern CPU and M.2 SSD this current method would still theoretically cause resume to fail at a degree. The verification should only check for the last couple MB and rollback a few Kilobytes on resume. And how is Firefox is not even trying to keep the connection alive?