sACN LTP? Guest Console?

This may not be the right place for this question, but I've been trying to get my head around this for a minute now, and I think this is a Gateway question. I don't have a lot of experience with multiple sources on a network, and I haven't had much luck. What I'm looking for is: if you have 2 consoles on the system both priority 100, with overlapping/identical patches, they're outputs merge in an HTP manner. Can that merge be changed to an LTP behavior? If so, I would think it would be at the Gateway level, so a gateway question.

Long story short, plugged a Guest's Avo into the network the other day, but neglected to put the house EOS into the show file with only the houselights patched. Everything worked fine, and exactly like I would have expected it to in HTP. The default/home data from the EOS severely curtailed the Avo's ability to control all multi parameter fixtures. Set his priority to 101, and he took over everything, so everything he didn't have patched went out. house lights, fixture power relays, etc... Nothing wierd or buggy, exactly what one would expect to happen. We quickly saw what was going on, said "oh yeah", got rid of my patch, and everything was just fine. Just like normal. But we talked about it later and he was adamant that it should have been LTP and worked just fine. Whoever grabbed the light and told it to do something would takeover those parameters. "I do this all the time at festivals and it works as LTP". I've known this guy a while and had no reason to doubt him, so I started looking into it. Turns out he's right, and you absolutely can do that with sACN, and I've found a number of products that do. So, how do you do it in ETC world? Console? Gateway? I can't find anything. It may just not be an option with the ETC gear, which is fine, it's not really a problem, I'd just like to know to say no, it doesn't work that way. Even better, a reason it doesn't. The hardware predates the current sACN Standard and we'll have it on the next update? It would confuse or otherwise upset some other aspect of production, like people, so they left that option out? Just saying "I don't know" to the hot shot Avo guy ain't a good look. It would be cool if it's a simple setting I'm missing that someone could point me to, but any thoughts would be appreciated.