He could pick now to dig deeper into the temptation of those offered semantics - what he imagines the ideal handling of the ruin to be versus the most likely outcome. That he is perfectly willing to entertain suggestions should Thranduil have them. It's an appealing distraction. An opportunity to solidify a plan between the two of them before adding, 'Oh, just one more thing—'

But it will all come out in the end, and he would rather seem genuine. So instead:

"Because I suspect Yseult will have some objections to the idea when I propose it, and I would like to be able to rely on yours and Rutyer's support."