Adafruit Feather 32u4 BLE compatible with Software SPI?
Read SparkFun's guide, Serial Peripheral Interface (SPI), especially the multiple slaves section:


Multiple slaves
There are two ways of connecting multiple slaves to an SPI bus:

In general, each slave will need a separate SS line. To talk to a particular slave, you'll make that slave's SS line low and keep the
rest of them high (you don't want two slaves activated at the same
time, or they may both try to talk on the same MISO line resulting in
garbled data). Lots of slaves will require lots of SS lines; if you're
running low on outputs, there are binary decoder chips that can
multiply your SS outputs.



On the other hand, some parts prefer to be daisy-chained together, with the MISO (output) of one going to the MOSI (input) of the next.
In this case, a single SS line goes to all the slaves. Once all the
data is sent, the SS line is raised, which causes all the chips to be
activated simultaneously. This is often used for daisy-chained shift
registers and addressable LED drivers.


Note that, for this layout, data overflows from one slave to the next,
so to send data to any one slave, you'll need to transmit enough data
to reach all of them. Also, keep in mind that the first piece of data
you transmit will end up in the last slave.
This type of layout is typically used in output-only situations, such
as driving LEDs where you don't need to receive any data back. In
these cases you can leave the master's MISO line disconnected.
However, if data does need to be returned to the master, you can do
this by closing the daisy-chain loop (blue wire in the above diagram).
Note that if you do this, the return data from slave 1 will need to
pass through all the slaves before getting back to the master, so be
sure to send enough receive commands to get the data you need.