Hello again, seems to be we share the same love for this frame. Closest recommendations I have for you would be:
Yonex Sv 98 - this is as close as you’re going to get from another manufacturer. Steve Johnson even switched from his AS to it for a while. It shares the same stiffness (67), string see up (16x20), aero dynamic throat, and has a somewhat decent feel for the power you get from the frame. I find it more relatable to the aero 98 now then the storm and it’s an older model. It is however the most one for one switch and I have played with both. Sw should be rather similar too but the AS swings easier.
Pure strike Vs/98 - I have not really used but the hoop looks like a slight more modernized storm hoop and has the Babolat branding with softer feel (but storms had decent feel). This frame I have also heard swings quite fast and is great at low tensions like the storm is. Frame also offers a thin beam profile that you are looking for.
@Trip had a point with the PD98 being a semi box beam hoop with a more so aero dynamic rounded neck compared to other frames. However the frame is a lot more powerful then a AS. Still worth a shot has it fits the stiffness criteria (67), string pattern, headsize, and brand. But do think the frame is unique and has decently different playing characteristics (I was on the playtest).
The prince beast 98. This frame is a 98, 300 gram, 16x20 racquet. So it shares a similar profile to the AS there. The frame does have a relatively thicker throat but overall an excellent balanced racquet that shared a more rounded modern throat with a somewhat boxy hoop. The stiffness is a bit lower than the AS but it compliments that with a higher power trajectory. It is pretty easy to string low and felt like it had great feel for the type of frame it is.
My final recommendation is the Yonex percept 97 or their previous line counterparts. It’s a lower powered spin friendly frame. Relatively thin beamed, great at lower tensions, swings through the air fast. The stiffness and feel dont quite align with this one but I felt like the touch and feel were an improvement and the ability to swing out mimic my current aero storms. With some tinkering of weight and tension you may have a valid replacement with it. I felt like the trajectory of the ball of the frame to be one of the most similar to the AS too. If it helps Jack Sock also used this frame before retiring after his stint with the ezone was considered I guess unsuccessful .
Let me know if you have another other questions or want more suggestions. The AS is truly a unique frame the teeters the like of tweener and player stick but almost is closer to a players frame compared to the modern spin 98 frames.