Is it possible to prevent specific backups from getting deleted? This question was asked three times, as far as I know, but none of these has an answer that I'm looking for:

1 – This unfortunately doesn't seem like a method to preserve specific backups

2 – This was marked as a duplicate of the above but I feel like it better suits the question. However, there aren't any answers for it

3 – This probably is my question best stated but there are no answers

So my question is, is it possible at all to prevent specific backups from being deleted from my Time Machine drive? Would it be possible to copy and paste specific backup to another location to preserve it and then restore from them later on? (I don't particularly think that it would copy a bootable backup, though)
Based on how Time Machine consolidates it backups, unless there is an unpublished method to modify how Time Machine is coded to do this (and I don't think there is), I'd say no, you cannot prevent specific backups from getting deleted.

That said, why are you trying to preserve specific backups, to what end and do you only need files from your Home Folder or the entire Macintosh HD? 

Additionally, Time Machine backups are not bootable and if what you're looking for is a full bootable backup of the systems at a given point in time, you need to make a bootable clone of the drive at that time. You can use SuperDuper!, Carbon Copy Cloner or from the Recovery HD, use Disk Utility or in Terminal from the Recovery HD use hdiutil, etc.