My 2011 built on an STI Edge frame didn't cost anywhere close to $4,200...in $1k+ range. As accurate, or better, than anyother pistol I own, and it just runs.... The only issue was a broken ambi thumb safety once after about 5 years of hard use which not atypical for
2011 (edited to correct typo) ambi safeties. I would check the Henning Group (
Henning Group Store - Battlehook, Blue Line, EDC and Competition products) and see if they have base pads that will fit your Witness and be legal in USPSA Limited division, which means the magazine has to be not longer than 5.561” (141.25 mm) measured along rear of magazine from bottom of basepad to feedlots. Pretty certain they do. For USPSA you would need a minimum of 3 mags, and preferably 4 for match. There is picture on how to measure in the USPSA rule book pg 115 and it is accessible on line.
I would work up a 130PF load if you reload (115 gr - 1,130 fps, 124 gr 1,048, 125 gr 1,040, 130 gr 1,000, or 147 gr 885) and go have fun. Or shoot a 170 PF .38 Super load, but it will be scored minor and have fun. Just my opinion but I think shooting factory would be too expensive and availability for .38 Super still isn't very good.
More and more people are using kydex hosters for Limited as opposed to race holsters -- much cheaper and better retention. I change to that several years ago for my limited pistol.
Doubt USPSA/IPSC will ever change the current rules unless to drop .357 Sig. Allowing a 9mm type case to be major PF in the Limited/Standard would overnight kill .40 S&W as a competitve round simply due to the increased magazine capacity. Many would start shooting 9x19mm in major if allowed like in Open. More plentiful brass and cheaper to load than .38 Super/.38 Super Comp, etc. Those who are die hards or don't have the $ for new pistols would continue shooting what they have but eventually the divisions would be dominated by 9s IMO.
P.S. Certain there are others who make base good pads that would fit your mags so search and make your own decision if that is what you want to do. Or, shoot what you have. Just realize that with 17+1 you can typically shoot two locations without reloading. But, you only have 2 spare rounds so if you need 3 makeups you have to reload early or do a standing reload....and 2 takes you to slide lock/empty mag if you engage the typical 4 targets, 2 rnds each at a shooting location or view with 2 makeups.