Leader for 40~80k tuna (90~180lbs)

Don't think you'd get much of an casting distance advantage going from 170lb to 150lb, but it doesn't hurt to do a few practice casts with each to see how far you're hitting. You could try finding tapered leaders heavy enough for what you want to do, I think Sunline makes some up to #30->#18 which is a bit lighter.

I mostly use hollow braid for casting lures just from the ease of rigging. My bigger 20K setup has 80lb hollow braid (around PE8 diameter 100lb+ breaking strength) ended with a spliced loop to use with a wind-on leader. I make up fluorocarbon wind-on's with 100lb fluoro and 200lb mono with the braided loop made from the same test I'm fishing (80lb). I'll use the 200lb if they're on the surface and biting, 100lb fluoro for some sinking stickbaits and if the fish are very picky. I've had better luck with fluoro resisting abrasion than mono. The connection for 80lb braid to 200lb mono is pretty smooth but I still like to keep it outside of the tip when casting.

If casting distance is a concern going with a longer rod might be the best remedy as painful as it is. I did find that guide layout makes some difference as well, I wrapped a rod with RV40/30's after seeing the new RF Ultimo's, haven't used the rod yet but from the practice casts they do seem to work better than MN's. Although I'm not sure if 5% extra distance is worth 10X the price.

Consistently hitting 60-65 meters casting actual lures is very impressive, especially for 100g. At that point lure type might make more of a difference than line. The Big Tuna 85 is a beast of a rod, it's surprising how well they can cast lighter lures despite having the pulling power.

Inline rigging is actually very simple, it just requires some tools to start but it isn't any harder to make wind on leaders. I can still use solid braid as the main line for some setups because it casts better than hollow, there are ways to splice hollow core braid on the end ~6-10 feet to create a loop or I just tie a bimini loop at the end. Here's what the bimini, spliced loop, and loop to loop connections look like.


I've seen the ultimate fighting leaders before, they're similar to a wind-on in reverse since the zylon end is on the side of the lure. It looks like they are mainly use to avoid tying a knot in heavy mono, but wouldn't it be easier to swage the leader to the swivel at that point? I can't tie a good knot in 200lb mono so I use sleeves instead, especially since the US 200lb Momoi is the same size as 300lb Ocean Record. These are the only ways I'll use that heavy of a leader. Ignore the backwards BB swivel, I wasn't paying attention.