"allowed for both" is correct and usable in written English.
You can use it when talking about a situation where two different people or groups have been granted the same permission, privilege, or other benefit. For example, "The company granted access to their special discounts, allowing for both employees and their family members."
It also allowed for both government and rebel troops to be stationed in Juba.
By the early 21st century professional boxing was allowed for both Chinese men and women.
Mr. Cox's design, however, allowed for both speedy data gathering and a relatively accelerated approval process.
Opening and closing arguments are allowed for both sides, although the House is allowed the last word.
We, in particular, consider the alignment problem when non-overlapping inversions and translocations are allowed for both x and y.
The pooled sample size (1,132 CNV cases, 822 controls) allowed for both model development and model validation to confirm the accuracy of risk prediction.
The inclusion of 3T3s and 7F2s in this study allowed for both direct comparisons to prior published work and a qualitative comparison to the morphology of the DPSCs.
Compared to other growth models, the BSF allowed for both symmetric and asymmetric growth curves, and thus the simulated data modeled the actual data quite well.
The seven distinct methods allowed for both real time quality improvement during the CHILA and long term planning for the next CHILA.
Conclusions: The PDL allowed for both a surgical and a nonsurgical multimodality method for treatment of precancerous lesions with minimal effects on the SLP.
But in this case, a simpler approach, like that adopted by Mary Zimmerman for her "Metamorphoses," probably would have allowed for both sharper clarity and a more persuasive sense of enchantment.
