@Ravness01 Yeah, the rifle and launcher together definitely play better than they do separately. Before a made a multiweapon I had a similar thoughts. On-paper a multiweapon doesn't seem like it would make a ton of difference since you'd think manually swapping weapons would function about the same way. But when you've actually tried it you go "ooooh, this works so much better. Why did I not try this before?".
A few suggestions for you to try if you want.
Fear Eraser (the Launcher's big laser) is really good single target damage IF the enemy remains stationary, meaning it's really great when a boss is stunned or downed. This PA has two stages that ramp up in damage depending on how long you hold it. After a few sections of holding the button there'll be a tone to let you know the laser's fully ramped and you can release the button to shoot a large blast for big damage. The finishing blast also goes off automatically if you run out of PP while shooting the laser (if it's fully ramped). To be clear, I would only use this PA if you can get to full charge.
Would also like to mention the launcher's weapon action, since you can throw it out and then have it restore your PP when it explodes (I think).