Anything is worth trying - again. And, good luck with your endeavor.
Over the years most every suggestion here, along with several others, have been tried, or were at least considered before being dismissed.
Back when IR started out it was only a 3-Gun event. To help draw in more shooters we would try things like:
Adding a Factory Class,
Shooting at not only 50Y/M, but also at 100Y.
Having a target set up similar to High Power For-Score targets,
Printing the targets in Red Ink.
Holding "Barn Yard" shoots where you could bring whatever you had, and we supplied the ammo.
But even back in the day nothing seemed to affect how many shooters would come. Not even when IR added the Unlimited Class and allowed for the use of One-Piece rests while shooting UL. It didn't draw in any more shooters than were already there. And the ones that did come out to give it a try often times would only be around for maybe a season or two, then fall by the wayside.
If you are looking for a tougher target you should check out the 25Y WRABF (World Rimfire and Airgun Benchrest Federation) target (their 50Y target is almost identical to the IR target, so that wouldn't help). The 25Y target has a much tougher "X" than the IR target as to score an "X" it's not simply a matter of just "touching" the outer edge of the line, but instead you have to totally obliterate the entire 2mm ring, and if any ink is left visible it becomes just another 10 (that ring also acts as the 10-Ring), and it's way smaller than the IR 10-Ring. My feeling is, overall you won't gain much if anything by changing the target as once everybody else is shooting the same target it all becomes the same thing - only different.
As for how to draw in more shooters: there is no answer to that question. 20 years ago things were more attractive as there were fewer, if any, "custom" actions showing up at matches, meaning any shooter could go out and buy a new or used gun, then modify it to their liking, and do so for less than 2 Grand. Plus, when it comes to the ammo: even though back then it was every bit as good, if not better than todays supply, ammo was so much cheaper as you could buy a case of the best at ±$750.00. Back then you could order 1 or 2 boxes of several different Lots and know you had time enough to have it shipped to you, do your testing, then order as much as you wanted as the suppliers would hold Case Lots of ammo for you while you were testing. There used to be more ammo available too so even though there were more shooters, the supplies would last for a few weeks at least. But, not today? You have to order blind and just hope your gun likes what you're about to feed it. How's that working for you?
And, how good were those guns back 20 years ago? As an example: at the 1999 Nationals my bench was situated between Bob Holbruner and Glenn Angles for the weekend. In the 10.5# and 13.5# Classes Bob was shooting an Anschutz 2007 and Glenn was shooting a Sako P94 that was set up for the Heavy Classes. Over the course of the weekend I watched as Bob set I think it was 7 World Records, and the great part was, if he hadn't Glenn would have as they were that close all the way through. Every target came down to the final shot. It was mind boggling. But in todays sport no matter what the Class you need to spend at least $3,500 per gun (plus scope) to be competitive, and then there’s the question of find the right ammo (that is if you can).
Don't get me wrong. I would love to see the numbers grow, but I just don't know what will make that happen.
Good luck with your quest. It's always been too bad that the numbers have declined as benchrest is so enjoyable and relaxing with what I've always considered to be the greatest group of competitors anywhere.
Just my opinion, but what do I know?
Dave Shattuck