Yes, they can be installed without removing the control arm and a little patience....... Tool will hold the fitting in place and helps start to thread, then you can use an open ended wrench. David
Those were going to be my next job, but first I went out and sprayed the snot out of the upper arm bolts and bushings with Lithium grease then followed up with WD40 to force it in. The next morning I went for a short drive while pumping the brakes to work the suspension a bit and by the time I got home the squeak had gone away!
Sorry to be late to reply - and it looks like you've got your issue sorted. To your question, yes I have the same brace and if you were to need to change out your shocks would would need to remove the whole thing. As you stated, the bottom flange needs to fit through when you pull it out.