You keep sticking to the "high velocity" statements. This makes me wonder if your expectation is to reduce the supersonic crack.
"Hollywood quiet" with a full power centerfire rifle is a myth. standard velocity rimfire (less than speed of sound) can get really close to "Hollywood" quiet.
If that is the case in your question, then it (suppressor) would have to slow the bullet down below or closer to the speed of sound before leaving the suppressor. in order to prevent the bullet from breaking the sound barrier. Which no suppressor does. There used to be a myth that suppressor did slow a bullet down floating around years ago by the critics of suppressors. They (suppressor) simply reduces the sound of the muzzle blast and gas expansion.
To the suppressor the 25-06 is no different than the 30-06 from which it's formed. XXX amount of powder = XXX volume of expanding gases containment / cooling. Smaller bore size just expels the bullet from the barrel faster, it doesn't alter the amount of expanding gases from a 06 case. Which is why I made the earlier statement of being rated for the 300WM which hold quite a bit more powder capacity. Baffle designs are as if not more of a important role as the length and diameter (volume capacity) of the "can" as they misdirect expelling gases slowing the gasses down from exiting the can as quickly thus allowing the gases to cool.
Now you as a shooter can reduce the speed of the bullet (sonic boom, aka supersonic crack) by choosing subsonic ammo or making subsonic which now it's not a "high velocity". My post is a attempt to manage expectations and fully understand your question.
A "over the barrel" or aka reflex design is what you may be seeking if so, a AB Raptor series, or maybe a Amtec Rongo series. Which means one can run a longer can without increasing the length at the muzzle vs a non reflex. As the design increases the blast area volume. There are several reviews on you tube of them. I'm sure there is other vendors but those are the ones that I found quickly.