This is a valid concern, I noticed ASPD boosting effects do close to nothing early on. I do believe this is official.
While the idea of these effects scaling with AGI is good - stacking ASPD bonus effects to get max ASPD without investing much in AGI definitely isn't good for game balance - the implementation could be better.
I don't expect Gravity to do anything about it - from what I see they don't care about low level content.
This is what I did on my private server : https://github.com/SeravySensei/rathena/commit/c9e3de250489044ec2f862e41f119e8f70f62686#diff-acba7818fb777457f5cbbcea9293f9c4
It basically allows a certain portion of the ASPD bonus to use a more beneficial formula below 100 AGI, without affecting anything above, scaling the effect more in favor of the better formula the lower the AGI is. (but as AGI itself is part of it, you still need at least some of it to receive any bonus, however it is an amount reasonable for the low level character)