You're welcome.

Yes, non-standard tunings can make it a little more difficult to figure out.  But it is still the same process of using ear skills & experience to figure it out.  And the more experience you have with alternate tunings, the more familiar you become with them.

Some alternate tuned songs can be played in standard.  It just depends on the specific notes & chord voicings used.  For example, if a song uses a drop D tuning (low E string tuned down), then there's no other way to get that note without tuning down.  Unless you just play a D chord & accept it as a substitute.

Typically alternate tunings are used in order to make certain voicings or lines easier or more musical to play.  Often it is combined with open strings that are retuned.  So, you might be able to play a reasonable facsimile, but not get exactly the same voicings & sound.

Kashmir by Led Zep is a great example of this situation.  I learned it in standard tuning by ear back in the day.  I was able to figure out what I thought was mostly right.  And since there are so many added instruments in the mix it's difficult to hear the isolated guitar.  Then years later I saw it in a guitar magazine with an article on how it used the DADGAD tuning!  I had no idea.  I tried it & it definitely sounded more accurate.  But whenever I played it since (cover bands, jamming with friends) I just use the standard tuning voicings I learned originally because it's easier for me & sounds close enough for my purposes.  But if I played in a LZ cover band, I would have a guitar set up in DADGAD tuning for that tune because it gets exactly the right sound.

Hope that helps!