A live album is still an "album" so there should be expected post-production. To what extent is up to the band/artist/production team.
You can have overdubs, performances from different concerts, full shows cleaned up, full shows warts and all. I think most, if not all, live albums are hybrid recordings, taking dry unmixed soundboards, mixing them, and adding in audience noise picked up from different microphones in the venue.
Some artists put out live albums to showcase new material otherwise not recorded in the studio. Often, a live album is a way to put out a commercial product to give listeners an idea of what their shows sound like. Unfortunately, these days, especially with older acts, live albums are a means to rake in some cash without having to make anything new, probably due to lack of creativity and/or pinch pennies out of loyal customers for their retirement fund/estate for when the grim reaper shows up.
Sounds like OP only wants live recordings, "bootlegs" if you will, audience recordings or straight-from-the-soundboard recordings, which are dry and unmixed (some instruments may dominate the others, or have a flat sound) all of which are plentiful on a number of sites, like archive.org for example. However, they are NOT albums.
I generally only listen to live music by bands and artists that actually DO original music live, and/or play in a way that is not captured in the studio that is very distinct from what they did in the studio.
This means acts like the Grateful Dead, Phish, Frank Zappa. Jams, different arrangements, high energy playing, different set lists every night or so, themed sets, etc...
DT mixed up set lists in the 00's and threw in the occasional jam but the songs were played the same way every night, and even the jams had pre-determined destinations.
I like Score because even though there are some post-production tricks on that album (JLB vocals, UAGM fix, etc..) they did a themed show, and played music not heard on their regular studio albums. If they had the budget I bet they would have tried to clean up the out of tune orchestra. Their other live albums are fine but nothing special (aside from a few cuts that are superior to their studio counterparts, like LSFNY A Change of Seasons)