If you look at the data I collected this morning, You would assume that the Mac version is not releasing memory correctly when compared to your Windows data using normal delete. In the first example look how the memory consumed goes up from the first load of A3 to the last load of A3.
First number is real memory consumed MB's and the second is Virtual Memory in GB's. My InTel macpro has 16 gigs of ram.

Open Poser Pro to an empty scene 129.2MB 1.15GB
Load A3, 226.5MB 1.25GB
delete
Load A4 252.6MB 1.27GB
delete
Load JessiG2 369.6MB 1.39GB
delete
Load JessiP6 277.8MB 1.30GB
delete
Load Laura 248.6 1.27GB
delete
Load Maddie 250.1MB 1.27GB
delete
Load Miki 1.0 271.0MB 1.30GB
delete
Load Miki 2.0 350.1MB 1.39GB
delete
Load OliviaG2 367.8MB 1.40GB
delete
Load SP3 255.4MB 1.28GB
delete
Load SydneyG2 387.7MB 1.42GB
delete
Load TY2 242.0MB 1.27 GB
delete
Load TheGirl4 264.1MB 1.29GB
delete
Load V2 245.0 1.27 GB
delete
Load V3 272.6MB 1.30GB
delete
Load V4 362.5MB 1.39GB
delete
Re-load A3 284.9MB 1.31GB
Yet the first load of A3 at the top was 226.5MB 1.25GB

Relaunch PoserPro into my biggest runtime V4 empty scene 133.9MB 1.15GB

1 load V4 with Morphs+++ and skin 245.6MB 1.26GB
delete
2 reload same V4 252.5MB 1.27GB
delete
3 reload same V4 260.5MB 1.27GB
delete
4 reload same V4 270.4MB 1.28GB
delete
5 reload same V4 277.0MB 1.30GB
delete
6 reload same V4 283.6MB 1.30GB
delete
7 reload same V4 289.2MB 1.31GB
delete
8 reload same V4 295.1MB 1.31GB
delete
9 reload same V4 301.5MB 1.32GB
delete
10 reload same V4 307.7 1.33GB
delete
back to an empty scene 263.5 MB 1.28GB
Again the memory consumed is slowly creeping higher.

Load 256MB pz3 with V4 and M4 and other props from Dream Home Media room.
644MB 1.66GB
shift delete left with 317MB 1.30GB
Quit PoserPro
Load same scene
normal delete left with 333MB 136GB

Again I see less memory available using a normal delete vs a shift delete when I delete everything and return to an empty scene.

That all said logic would tell you if Poser really released everything in memory you would return to an empty scene with approx 130MB consumed, not approx 317 to 330MB's.

Gary

"Those who lose themselves in a passion lose less than those who lose their passion"