The phrase "allow only a tiny" is correct and usable in written English.
It can be used when specifying a very small amount or degree of something that is permitted or acceptable.
Example: "The new policy will allow only a tiny fraction of the budget to be spent on entertainment."
Alternatives: "permit just a small" or "grant merely a slight".
The microscope flashed laser light onto the samples in a way that allowed only a tiny region to glow at a time.
The problem with using systemic virotherapy is that the immune system and tumor microenvironment could seek, sabotage and destroy virus, which allows only a tiny fraction of viruses to find their way to tumors.
North Korea, a country that is cut off from much of the global economy and allows only a tiny portion of its population to have access to the internet, has been building up its cyberattack capabilities since the early 1990s, selecting teenagers and teaching them to be hackers, according to South Korean officials and defectors from the North.
That treaty, which became defunct when the Soviet Union collapsed, expressly prohibits the deployment of national missile defenses and allows only a tiny, highly localized defense based on old, ground-based technology.
A Foreign Ministry spokeswoman said today that a new law, formally approved at a Cabinet meeting Friday, would allow only tiny amounts of heavy water to leave the country, and then only for research.
The abstemious Robinson allows Ames only a tiny, and therefore especially poignant, reaction.
Several years ago, Hawthorne's council approved an ordinance allowing homeowners only a tiny amount of time to display signs — a month before an election and a week after.
Culling is allowed only in tiny numbers: in France, for instance, 11 wolves may be harvested this year.
Instead of an inkjet's tiny nozzle that allows only droplets with individual cells to squeeze through, Dr Forgacs invented an extrusion-based printing process that uses a syringe with a needle or micropipette with an orifice that may be as large as several hundred microns.
To nurture domestic film, it allows only 34 foreign films to be shown annually, an increase from the previous cap of 20 but still a tiny number.
