Can we install super xci files with tinfoil?
Yes you can, however I encountered some problems installing them. Sometimes it work, sometimes it doesn't. If you run into any problem with a super-XCI try enabling the "convert to standard crypto" option. Worked for me with DOOM+Update.
any good tuts out there to temp swap over to atmosphere? can you carry save files over
Depends wether you are using sysnand or emunand. As far as I know, the only option for dual boot are by using sysnand (the easiest since you only have to copy hekate and atmosphere files to your SD) or emunand hidden partition. I made it work with my emunand hidden partition by setting atmosphere to look for emunand in sector 0x2, which is the sector used by sxos in the SD for its emunand.
Sadly, I do not have any tutorial now, try googling "dual boot atmosphere sxos", you will find something.
Still, if you want to completely migrate from one CFW to another, you can use NxNandManager, it's a program that will transform your emunand to work on atmosphere. Remember that you will still need sx boot.dat and license.dat in your SD to chainload the hekate payload from the sxos boot menu.