Yes !

Aspect ratio is an enginering coefficient that has no direct physical intepretation or tight relation to a fixed natural process. Much like prismatic ratio or indeed "max hull speed". Such coefficients or numbers can only be accurately applied over either a limited band of values or for a select group of "situations"

You can only use aspect ratio meaningfully when different designs are close enough to one another. With increasing difference in overall shape the inaccuracy of the results increases also. That is engineering as opposed to exact science. Engineers will often reduce far more complex phenomena into simple rule of thumbs or approximations. The concept of aspect ratio is well on the engineering side of this split.

The expressions defined to calculate aspect ratio reflect this.

One of the most dominant definitions is :

Squared Length of span perpendicular to the flow / total surface area.

As both are fixed as maximums per F16 class rules the maximal attainable aspect ratio is fixed as well.

The effect that changes of the shape will have on the overall performance may however change. I didn't make this definition, I'm just reporting the commonly accepted framework

Wouter