I do agree that the 58/15 LT's in a Custom 24 does seem an odd choice. The 58/15 LT's are a fantastic Pick Up and offer a lot of clarity but are quite 'vintage' with the low turns/low output. It really does suit the McCarty's inc the 594 and Hollowbody's. Maybe who ever did the Wood Library order wanted that vibe - Vintage meets 'New'.
Personally, I am not a big fan of the high output hot pick-ups - I am sure these would suit a Custom 24 perfectly well but I would rather add to the output with pedals to get the 'metal' scream if I wanted. Hot Pickups tend to break up cleans and not so easy to roll back the volume to go from cleans to break-up to crunch. I do like my 85/15's in my Custom 24 and these do have a bit more 'punch', a bit more 'modern' sound. They aren't exceptionally 'hot' but they do suit the Custom 24 well - at least for me.
I think the 58/15 LT's would have a bit of mismatch feel to me in a Custom 24 between the sound and the look - A 24 fret modern guitar with a more vintage sound. You can of course use some pedals to give it a bit more oomph, a bit more bark and growl. I have the 58/15 LT's in both my 594 and HBii and find them perfectly suited to these instruments. I wouldn't consider swapping them out. I think could cope with them in a Cu24 as well but I do think the 85/15's are better suited to that instrument.
In fairness though, I have not heard or played a Cu24 with 58/15 LT's and my thoughts about them are based on my experience with my instruments and the way they sound. Picking up my Custom 24, with its thinner neck and 24 frets, to me at least, I think 'modern' - even if its not ultra modern with really hot pick-ups, but I get that 'vibe' from it. I guess the 80's is now 'vintage' of course but its not 'classic 50's/60's' vintage, modern-vintage?
Anyway, that's my take on it. I guess if I picked up a Custom 24 with 58/15 LT's, I could get used to it, make it work for me. If I felt something wasn't quite right, wasn't what I expected or was looking for, I probably would look elsewhere, try a regular 85/15 Custom 24 and see if that had the right vibe. At least I would know whether its the guitar or the PU's that were not right for me.
Unlike a lot of people (it seems), I like to buy guitars on how they sound, not buy in the hope that I can find the right Pick-ups to have a guitar I liked the look of and hope to get the sound the way I want later. As such, I haven't swapped out Pick-ups - I bought the guitar because it sounded the way I wanted/expected it to sound so don't mess with something that ain't broke. I know that a LOT may not have the same approach as me. It certainly seems like its part of US culture to buy something and then constantly change/mod everything - whether that's a car or a guitar. Not a criticism at all, just an observation. Whether its because I am British that I expect things to be 'perfect' when I buy and not have to spend money to 'fix' things or not, I don't know but I wouldn't buy a guitar if it doesn't look, feel and sound right so require no after-market parts to correct things - like 'sound' (so no need to change PU's), tuning stability and/or ease of changing strings (no need to change tuners, nuts etc). The only thing I expect to change are things that wear through natural usage.
Whilst that isn't exactly relevant to the topic, I thought it was worth mentioning so you may understand my viewpoint. I would rather try adjusting everything at my disposal rather than switch PU's but I probably wouldn't have bought a guitar if I thought it didn't sound or feel right in the first place. At my disposal, I have a multitude of different options that I can adjust - assuming the guitar is set-up properly - PU's at the right height. I can either work back from the Amp or forward along the signal chain from the guitar. Depending on your pedal board and/or the pedals you own, the amount of 'tweaking' is limitless. Sometimes it seems that people would rather switch PU's than to make adjustments to their Amps EQ, change the gain, change Pedal settings and/or order. Maybe all that is needed is a 'boost' that you didn't need with a different guitar or an EQ adjustment somewhere in the chain.
I have watched Video's of people A/B'ing 2 different guitars and complaining that one has too much 'mids' compared to the other, that they like a 'mid' scoop sound - yet their Amp is set everything at noon. What that says to me is that the other guitar has 'little/no mids' so if you prefer a more balanced sound across the EQ, you can't add 'mids' on the one guitar but, if you prefer a 'mid' scoop, you can take the mids out with the EQ - much easier and better to shape your tone. In my opinion, its better to have and not need/want, than not have but want/need.
Anyway, the TL/DR is that I like both the 58/15 LT's and 85/15's in the Guitars that these are generally fitted. I don't buy guitars that don't sound right so have no experience (or desire) to swap PU's and would rather adjust settings along the signal path and even pedals and their order rather than switch PU's. In other words, I would change EQ's, add in a boost or more gain somewhere if I wanted a bit more oomph rather than swap PU's to get a hotter set. However, I also know that my culture, my opinion may well be different to others and wish the OP good luck in sorting out their concerns in whatever way suits them best...