[susan53]

No - why? It follows the rules of adverb formation and is fully comprehensible. The fact that it's unusual is irrelevant. That's how language changes - someone starts using a word or a form in an unusual way, it catches on and bingo. If this hadn't happened in continuation we'd all still be talking like Chaucer. (Well actually we'd all still be grunting like stone age cavemen, but never mind ...)

I think that's what's happening with the comparative too. Gradually the -er/-est endings are being replaced by more/most. English hates endings - we got rid of the noun endings ages ago, and all verb endings except the 3rd person -s by several hundred years ago. So why not adjective endings too? At the moment we're in a transitional stage, and with a lot of one syllable adjectives, and nearly all two syllable adjectives you currently find both. Here are some examples of more/most with one syllable adjectives :

... and this is even more true when you are ill.
... that if I told anyone, it would make it more real.
Hailed as the `most real, meatiest, heaviest metal album of 1994" by ...
... minimum sentences making drug laws more fair or just more severe?
the city is a lot more quiet and a lot more calm than it has been

When one syllable adjectives make up the first part of a compound adjective, the "flexibility" - ie the ability to form the comparative in either way, is even more obvious :

.. the opposition party's widest-ranging policy review
... the reforms, which are generally agreed to be the most wide ranging and fundamental since ..
at a time when they are most hard pressed at work
Often the World Bank and the IMF have required the hardest pressed countries to adopt
until a more long term solution is found
a fundamental error which will exact an even greater toll without a longer term policy

and look at the two-syllable words :

... it is very rare in infants and becomes much commoner in the middle and older age groups.
Skin cancer in Britain is becoming more common ...
The alley grew narrower and then ...
The longer the lens, you use, the more narrow the angle of view...
and breathing often becomes more shallow and rapid.
This branch canyon was much shallower than Many Ruins
...it seems even more stupid now.
It gets stupider still.
the city is a lot more quiet and a lot more calm than it has been.
She was much quieter...

I'm willing to bet that in a couple of hundred years the -er/-est endings will seem archaic.

It's a pity I won't be able to collect my winnings, she concluded - smiling friendlily.