I've done that procedure many times. You'll gain a couple of inches of extra space if you loosen the two subframe bolts (21mm) on that side.
There really isn't much space to effectively compress the strut spring when it's installed. To compress the spring a little bit (to aid in getting the knuckle installed/removed), I have sometimes placed a small 'bottle' jack on the knuckle to push/compress the strut assembly.
Using both the subframe and bottle jack method will give you plenty of room to work with!
