We avoid springs if possible in our projects. We can find in many cases that there are locations which will satisfy the requirements if rigid supports are placed at these locations instead of using springs. We need to find out the appropriate locations. These are only my own views. May be mistakes!!! If a spring is placed and which gives even higher loads then what is the use of that spring. This is what I meant in my previous response. You can call it wrong selection of spring rather!!! Or placing at the wrong location. In the file attached place the spring at node 40. Let Caesar2 design the spring. The result is different. Now the question may be of space availability etc. Or try with location node 55. In this case add a (+LIM) with 0 gap at node 60. Here also let Caesar2 design the spring. You get another result. So it is not a must to place the spring at a location where it can produce adverse effect.
Regarding the theoretical installed load and actual installed load refer User Guide page 7-18 (Hanger table with text). Refer my previous response above.