I did the interlocking overlap style of Allure in a TT and went full floating. The planks are somewhat flexible but are plenty firm enough that they will not buckle or ripple if the slide rubs on it some. If enough pressure is put on the Allure from the slide to buckle it, there is something majorly wrong with the slide alignment.
One tip I found if you use the interlocking adhesive: On a flat surface they work perfectly as is. If you lay it over a irregular surface, a small bump or if they will be flexed some, the adhesive will pull up some. I put a small line of superglue into the problem areas of the overlap and pressed back together for a couple seconds and never had a problem with separation again.
So, while you certainly can lock it down to the subfloor, I never had the need.