Hopefully one of the Mods will get this transferred to the BP forum.

The only way to tell if switching to 3fg would have an advantage for you is to try it and see. Some guns and/or bullets prefer it and some don't.
You're correct in believing that the smaller 3fg cut will ignite faster and build more pressure at a faster rate. So if you're using true Black powder, you need to reduce a 2fg load if you try 3fg. So for your 95gr 2fg load, I'd start working up from 80gr of 3fg in 5gr increments to see where your best accuracy is found.

I lot of people do use 3fg in sidelock-type rifles, so it's not uncommon. Also the smaller loads of 3fg will make your can of powder go further as well (6 to 10 more shots to the lb).

Now, if you try using 777 powder in 2fg & 3fg cuts............the rules change a bit. There is VERY little difference; pressure, speed, or performance wise between the 2 cuts - so you do not have to reduce 3fg loads......unless you find better accuracy there. I played a lot with both of these in my Knight in-line and found that my heavier sabot bullets (over 300gr) like 3fg 777 better than 2fg, but any conicals, powerbelts, or 300gr or smaller sabots did better with 2fg. And I did not have to reduce my former 2fg loads when going to the 3fg, as there is less than 100fps difference between the 2 of them when used with the same bullet.

So, all you can do is try it to see.