You should, but only Gabriel Knight 1 and 2 are DOS games, GK3 is a Windows game, so you're stuck with the DirectDraw / Direct3D mixture the game uses.
Yep, GK3 is using an odd engine, no doubt about it. If you succeed in setting up a decently high resolution the game really chuggs--so much so that I settle for 1024x768...!
SVN-Daum is ace though, but the latest build had sound issues (sound went mute random) for me in GK2, so I've used vanilla DOSBox SVN for it. In general, I love the Direct3D renderer for DOSBox, but I don't always use hq filters, sometimes I prefer something softer like advanced MAME or the xBRZ one that Daum ships, too.
Yes, I have the occasional drop out of the audio in GK2. But it's now mostly alleviated.
I found that by changing the resources the game allocates for my dosbox sb16 config to irq=5 dma=1 hdma=7, that the game loads much, much faster. I previously had it set to irq=7 dma=1 hdma=7, and the game took a long time to load as it configured itself for my settings, and the audio drop outs were much worse (game seems hard coded for irq=5 in the DACBLAST.DRV, and the setup program, install.exe, doesn't allow for selecting IRQ & DMA manually.) I also lowered the cycles the game uses from 16000 to 10000, which seems to have helped (surely better than the 3000 cycles the auto setting provides for), and changed the resource.cfg settings to minMemory= 3600k and smartdrv = NO, which may or may not have helped--haven't really decided on those two...;) Anyway, the dropouts have all but ceased atm. In resource.cfg I also use general midi drv for music along with soundfonts through Coolsoft's Virtual Midi synth (which I'll bet you are using, too...;) Everyone on Win10 who games should be using it, imo.)
Also, I found, as you report, that the Jan 2015 svn-daum dosbox does indeed cause problems with audio in some older games, so I took the Jan 2014 svn-daum files version (which didn't have that problem AFAIK) and overwrote them with the Jan 2015 svn-daum version--and that cleared up the audio in svn-daum for me!
You know, I'm so lazy I never bothered to specifically isolate which files from the Jan '14 version it is that correct the sound problem...;) Ah, well...!
Maybe I should try the 32-bit dosbox.exe version of svn-daum...Hmmm...wonder if that's all it takes to keep the sound from dropping out at all...! It'd be just like me to have been chasing my tail here...!