I was going through the whole list of packages installed on my Jolla phone, and I noticed that one of them is partnerspace-launcher-0.0.5-10.4.2.jolla.armv7hl. According to my update records Uitukka update installed v0.0.2 and Vaarainjärvi had v0.0.4. So... probably the partner space idea is not a new concept of the tablet and SFOS 2.0, but a capability that is already in our phones, just not fully deployed yet.