Stacking Powder Risers?

[Loki]

I had gotten to like the Auto-Disk Pro's and have been using them for quite a while on my progressive, but I eventually got a little frustrated that you had to accept whatever hole would drop "closest" to what you wanted to.
After I got a chrono, I wanted to do some fine tuning of my loads and I never could get the adjustable charge bar to work well for reasons people have posted elsewhere.

Fast forward, and I bought an Auto-Drum and immediately wondered why I didn't get one sooner. After a proper cleaning and conditioning (graphite/dryer sheet wrap), it immediately worked as advertised, and I found that the instructions of "one facet turn = .1gr" was really very close. The Auto-Drum granted my wish of adjusting to whatever load I wanted.
However, what I ran into was that there was NO way to set it up on my progressive to clear the stuff next to it with a Riser in the way that the Riser allowed the Auto-Disks to work well.
The Auto-Disks worked fine with the Riser, but not the Auto-Drum.
Then I got a brain storm of adding the other Riser I had and stacking the two of them, and that solved all my clearance problems.

Are there any Devil's Advocates here who can come up with potential problems with using two Risers instead of just one?

[Tom Myers]

I stacked up six of them and used them on my Loadmaster to auto-drop-tube black powder into 45/70 cases. It worked beautifully.

[Ranch Dog]

I stacked up six of them and used them on my Loadmaster to auto-drop-tube black powder into 45/70 cases. It worked beautifully.

Why so many?

[Loki]

I stacked up six of them and used them on my Loadmaster to auto-drop-tube black powder into 45/70 cases. It worked beautifully.

Seriously!?

I guess I'm good to go then.

[Tom Myers]

I stacked up six of them and used them on my Loadmaster to auto-drop-tube black powder into 45/70 cases. It worked beautifully.

Why so many?

These loads are for Long Range Black Powder Cartridge shooting (1,000 yards). Drop tubing enables one to get more powder in the case and the uniform packing and subsequent compression of the powder results in near single digit Velocity Standard Deviation and cleaner burn with less fouling to contend with.
Drop tubes of 24 to 36 inches are not uncommon but, for my purpose, a slow pour and drop of 10 to 12 inches is adequate with Olde Eynsford powder.

[Ranch Dog]

Well, I've seen the results from your shooting and it is impressive!