I suspect we could get 50 people with both PLT statuses just here on FT. I'm LT PLT in both - they may know who I am, but I've seen no action resulting from it. (But I guess a 10,000 is technically 50+)
The typical argument against diversifying is that you're giving up the benefits you've earned after you've earned them. But you have enough nights to be top tier in 2 programs and I suspect could get a match to avoid the "no benefits, still earning" phase.
I did the same many years again, matching my MR PLT to SPG, then earning PLT in both for a decade, diversifying but never missing out on benefits.
It's a valid approach - my recommendation would be to avoid diversifying into two programs that then merge and waste the effort
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If you stay where there are Hyatts, they've traditionally had a good program, though limited in coverage. My experience with Hilton has been that they're so bad, I don't know if even top tier would be worth it.
But there's also nothing fundamentally wrong with sticking with SPG. I still think it's the best program . While the earning ratio turns out poorly in some analyses, they never consider all of the additional opportunities top tier elites have, and I think it's at least as good as the others.