Keeping in mind UsoppNoKami's post, I still have to recommend against using an LPS, as per earlier comments from AtomicBob and me.
One has to ask, what advantage am I getting when I use an LPS? Most of the advantage that one thinks one is getting is higher current capacity and lower noise.
On the noise issue, measurements have shown that the Plat has a very low noise floor. Not much improvement, if any, with an LPS. Certainly no audible improvement bc noise floor can't be heard.
As for current, the SMPS that mates with the Platinum can deliver much more current than the amp can ever use. It is over specified. Thus, any additional current capacity that one might get from an LPS is not useful.
The risk is that the higher current capacity is in the form of big electrolytics at the output of the LPS and lack of current limiting on startup (as already discussed). And this is exactly what you don't want dumping into the control circuit of the Platinum.
So, MHO, is that there is little, if anything, to be gained, and definite risk of damage.