I've always found that the ques are pretty instant for solo. It would be nice to que from anywhere so that I can continue doing what I wanna do. However the downside is, most people might be in combat, etc, and suddenly your team of 3v3 is now a 3v1. I love the idea, and personally would love that, but I know that this would happen to me.
This would be heavily abused to reset cooldowns in WPVP or quickly escape combat with other players. This would in turn hurt the SoloQ team because they aren't joining the fight to win, just to abuse it's mechanics.
This has a simple solution in combat, it would not be possible to log in or accept a queue. If the player leaves the arena before someone dies in the arena, he will be "banned from joining" for 30 minutes.
What I see is finding problems, but not solution which is not helpful to anybody.
It's very helpful and encouraged. Perhaps not helpful for the suggestion, but very much so for us in making a decision. No one who sees an issue with any suggestion should ever feel they shouldn't mention it if they can't also give a solution, as it isn't on them to fix someone else's flawed suggestion.
Nobody will sit and do something just because it's suggested as base idea
Probably 99.9% of what gets accepted goes like that, because they were simple base ideas, which respected the guidelines we have for suggestions right out of the box. If an idea requires thinking about side-effects and solutions, it's already at a high chance of being a poor suggestion, more often than not requiring more work than it's worth or simply being a personal/niche wishlist item, not something that has enough global server impact to justify it (and that's assuming they got through the suggestions rules, which most don't).