Hopefully this list is the right address for this question. I know that running a hidden service and relay from the same tor instance is not advisable to say the least (https://trac.torproject.org/projects/tor/ticket/8742) but what about running a relay and HS on the same ip, different instance (multiple virtual machines using same public ip for example). The purpose of it would be to have some decoy tor traffic (so it looks like relay is creating it not HS)

I can imagine some traffic analysis could be done if HS picks the relay on the same ip as RP or IP or guard node. Are there any mechanisms in tor to prevent that? What other downsides are there for running a setup like this?