I have enjoyed watching this topic with interest, as I did exactly the same job on my ’93 +8 last October.
I did not use any spring compressor at all.
I found that approach fine the first time I did the job when I had old springs on the car. When I put new ones on, the new mains were at least an inch longer than the old and
very difficult to compress enough to fit. The new springs, incidentally, transformed the suspension which had previously had a habit of bottoming out.