Deaver Stage 3 Question/Help

I currently have Deaver U402 Stage 1's on my 16 TRD Offroad A/C. I had the leafs before adding a Smart Cap, and now, between the additional weight of the cap plus extra shit I've found to constantly keep back there, my bed weight is never less than 400 lbs constant, fairly evenly distributed. The stage 1's are actually holding the weight very well, I'm still netting an inch of lift but they have gotten soft and when I go hunting, which is about once a month, I add a few hundred more lbs at which point they get really soft. I'm also going to be building a bed drawer system that I expect will add another probably ~150 lbs.

Would Stage 3's provide excessive lift with only 400-500 lbs in the rear? I'm not concerned very much with a rougher ride day to day as I'm just trying to stay at around 2.5-3" of lift with 400 lbs minimum in the bed. I'm not sure when I'll get around to doing the bed drawers, it could be next month or it could be a year down the road, so, I'm trying not to end up buying all three stages of Deaver U402's within a year.