I’ve been researching and found there might be a solution. You can by these adaptors on ebay - “ZIF 1.8 to 50pin 1.8 micro-ata adaptor”. This allows you to connect any ZIF drive (5mm in height) to your X505 but there are issues regarding limited space inside the case. I recall reading a topic where removing the outer enclosure of the SSD will leave you with the main board measuring 3mm in height. If that’s the case then I don’t see why this upgrade isn’t possible.
In theory the front end of the SSD should sit just above the ZIF connector on the adaptor. Length wise, ZIF drives are also 1cm shorter compared to the equivalent 1.8 PATA HD, this gives you a bit extra space to place the drive.
This is just a theory, which I’m happy to try once I get my X505.