Thinkpad T520 SSD place question

Hello,

My T520 Lenovo Thinkpad notebook has one HDD drive in hard disk drive slot.
I have a new SSD and a HDD caddy which I received from Aliexpress.

I planning install SSD and use both drive - SSD for system, HDD for media
data.

My operating system is Linux Mint 18.3.

And now I have a question - what is the best place for SSD and for HDD?
On the one hand it's better install SSD to hard disk drive slot, and HDD to
ultrabay.
On the other hand - I remember two things:

   - Thinkpad models have "Spill resistant keyboard", and I suppose they
   have special route for liquid outside hard disk drive place. I don't know
   anything about spill protection ultrabay area.
   - Thinkpad notebooks have an "Acive Protection System" (airbag) also. Is
   this technology will work for HDD in ultrabay slot? Is this technology
   support only windows operation system?

Are there someone who have an experience for install on thinkpad two kind
of dive?
What is the better way?

-----
С уважением,
Иван Владимирович Ниагара
Mail: [email protected]
Phone: +79232350060
Skype: ivan.niagara
Best regard,
Ivan Niagara

-- 
The linux-thinkpad mailing list home page is at:
http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad