.... More on reg less on hammer and vise versa will give you the same speed .
I am seeing a lot of answers, but no one actually answered you specifically for the above...
Yes, you can get the same speed going either process, but the results would be much different at the muzzle.
With a higher Reg and matching hammer hit energy (hammer spring and hammer weight balance) you will get a smaller air blast at the muzzle that can unbalance the pellet skirt. Going from there tighten the Valve spring monitoring the speed, take away maybe 10-15-20 fps from the Max and that will shorten the air blast inside barrel hopefully before reaches the muzzle.
Internal + external airstripper will help you greatly.
Sorry I don't know your gun dictionary I have the .25 Impact MK2 also couple .22 liners as well but no .177, and this shall give you some picture.
To fully tune your gun - or just any gun - sometimes a tin of pellet is just not enough. You change the pellet weight you retune, you change the caliber you retune.
Take a (paper) notebook and a pencil and document all your steps. Always change only one thing at a time and write it down. When you got couple pages of data, grab a beer and start tinkering.
You will see a first.... smaller calibers need more air and higher pressures, you can start from there. Then change to higher caliber and examine with that given Reg you will turn the Hammer Spring Tensioning Wheel to lower numbers to eliminate the high burst.
Yes, it is possible...