Cool to see uplexa represented in Medium, thanks for posting. I would recommend not changing the difficulty over time, as that might deincentivise later adoption, by granting unfair advantage to those entering earlier, just like old world capital, seemingly to perpetuate inequality.
If it is one of the best to mine already, then why change it? Don’t fix it if it ain’t broke, the only reason for wishing to change it appears to be driven by those with already a stake in it, to give them capital advantage over those that might follow.

Don’t try to copy Bitcoin, appearing to enforce scarcity, it is a very special case, being the first ever pow token, nothing can change that.
Reputation, is what will maintain the value of all tokens that turn out to be successful, always requiring exactly the same energy to create seems a very honest and reliable quality to me, why change it.
In its current form, assuming it will always be mineable, and assuming the difficulty will never change, it appears to fit the requirements of a personal token, as identified in my story about the Bitcoin Kardashev Hinge, and its sequel, the ICO of all ICO’s, I recommend reading those, and really hope uplexa turns out to be the personal token described there.
I would try not to succumb to the temptation of greed, that drives most investors (profit), all of that will end very badly, when all capital ceases to have value, mathematical proof of that, and the reason why Bitcoin is an exception, is in the Kardashev Hinge Medium Story. You will hopefully also see there how the greatest utility a token could possibly have, is being useful to all of humanity.
The winners will be the tokens most closely reflecting the qualities of the energy of sunlight, an exactly unknown quantity at any time, but always reliable, always constant, received through plants, just as attractive to the last adopter as the first, is what I would say, and ask, and even pray for, if there ever was such a thing worth doing.

Believe it or not, uplexa, if it just carries on as is, could turn out to be part of the solution to all of the current problems of humanity, including even the climate problem, the solution is technically the end of capitalism, and the beginning of something new, much better than we ever saw before, money as sunlight, instead of the deadly money as debt.

We are migrating from the bad to the good, but the bad will never admit it, capital is already declining.

Have a look at the long term gold vs Bitcoin trend if you are in any doubts, Bitcoin isn’t the capital investors think or wish that it is, it ain’t what it says on the tin, it is something much more, of similar significance as Uriel’s Engine, believe it or not.

But uplexa could have its place within the same common schema.

I will provide links to the stories later when I have use of a device suited to the task of adding links, but for now they can be found in my profile, and in a Medium search.