Multi-Clienting

[Can]

I support the dual client, I used to play in euRo official server and it was allowed there and have not really caused any game-breaking problems. However, there are some different mechanics at hand here, due to low population and custom events.
For a lone wolf player such as myself, being able to buff or endow yourself is a huge difference, especially endow, that may allow me to build 4 carded weapons instead of using crafted elemental weapons, maximizing the effectiveness of the characters we have.
On the other hand, I think you should only allow the usage of multiple clients outside of WoE times. In a highly populated server a WoE would include hundreds of people in a castle, which would make the occasional dual client quite negligible in that body mass, but with so few people doing WoE on this server, extra clients can really be tipping the balance.

I don't see how this hurts anyone's party chances. Personally, if I have a chance to party, I would take it instead of hanging with my 2. account 'slave', it is more fun and people love socializing on this server. As someone said above, the reason parties are not happening is because people are already maxed out, lots of 99 rebirths fully geared, who have no need of running any parties.
I'm probably a player that hangs out solo, a lot more often than others. And I have usually had trouble finding parties for "party classes" such as priest, wizard or crusader, therefore I leaned towards agility based soloer classes, such as rogue or monk. And when I did get into some parties, they would be at least 5-6 people parties. So I figured, this is what people on this server like to do, whereas the go-to party size on my old server was 2-3 man smaller parties. I mean to say, the bigger sized parties we have more often on this server would not be hurt by this change, but this change could make it easier for 2-3 man small parties to be formed.

If you can find a way to prevent these WoE and BG issues, I'm for it.