Topic: input monitoring

I've been using the Dakota(/Montana) for years but have never used input monitoring through it since I have always run the lightpipe audio through a digital mixer (Behringer DDX 3216) first for monitoring, then out the DI busses fom there to the cards/DAW. Now I'm thinking about running straight from my preamps (3x Presonus Digimax) to Dakota/Montana and using the input monitoring patchbay to send the direct in signals back out to be sent to the DDX mixer for monitoring. So my question(s):
1. Is that putting a large strain on the cards/DAW if I was to input monitor 24 channels all at the same time as recording all those channels?
2. Is there any latency in the input monitoring when doing this? Just the buffer size (in my case, 512 samples)?
On a side note, is it even worth changing the signal path? Since I do not want to process anything that will be recorded with the digital mixer, I assume it would be better to get the signal to the Dakota/DAW first, then to the mixer for monitoring.  I do not want the DDX deteriorating the signal or creating jitter.