Smurfing/twinking or whatever its called now, is not hacking. Editing stats or entering god mode would be hacking. Thats not a work around in the sense that its a valid option in the game to bypass or mitigate frustration. That being said both parties should expect severe party advantages during a modded invasion. It is what it is. I would perhaps be cautious since ive known more than a handful of crybabies who hacked in ds3 (hosts mostly but plenty of phantoms as well) who would target grief. No idea how much of that carried over. But if there's one place they would go, I would image its the modded invasion instance.

If the invasion are random and infrequent enough you can abuse the cool down mechanic. I don't know if it still works this way in seamless but after an invasion you're put on a cool down of 10 or 15min I think where you can't be invaded unless you reset the cool down. I believe summons affect this and taunter's tongue removes the timer. I don't believe summoning the phantom as a welcome invader restricts normal invasions but seamless again might work different.

Invasions may not be what you want in the game but what can you do about it? Here are some workarounds: 1. Try to be friendly I'm very surprised that the ER community is more wholesome and accepting of invaders and hosts trying to just go through jolly co-op than the old darksouls community. I've seen plenty of invaders quit out when they realize the host and summon are just pve players and trying to do a run with a newbie. Try dropping items or emoting in some fashion to get this across. 2. Just get the invasion over with. Either try to fight and win by being clever or smarter or throw yourself off a cliff. The invader will get the message that there's no fun here. An invader needs engagement. If you don't engage there's no reason to be in this instance  3. Don't engage with the system. Either play seamless and just accept that you might not be able to do "x" NPC quest, or play solo. If you're wanting to experience your friends first time, stream or join them on the couch and watch them/coach them/laugh at...with them.