Maitimo is very busy, which is good, because he likes being very busy; there's an irreplaceable satisfaction to pursuing seven lines of thought at once and watching them wind back together as a solution to his problems. And there are a lot of problems. They don't know if Vanyel is dead. They know Leareth isn't, but that it'll take a lot of work to make him once again as vulnerable as he is now; they're checking halfway around the world for missing mage-gifted boys, following every tedious lead, wasting precious time and resources on tracking down runaways and idiots who drowned in the river.
He knows, roughly, the route Leareth will be taking. He'll want to go north; it's where his army is. He won't chance the Pelagirs, even though the Star-Eyed isn't working with Vkandis on this (Maitimo is working on that), he can't chance Valdemar or Iftel or Karse. So wherever he started, by now he's probably east. Mostly moving on foot, since he won't be able to easily Gate places he hasn't seen. It is not straightforward to find a man in the wilderness, not when you've never met him (and as far as Velgarth's magic is concerned, they haven't met).
But it's not hopeless. Leareth never explained his system of supply caches in any detail, but the fundamental concept is simple: he had to be able to rederive their locations without any specific memories. The locations therefore had to follow from who Leareth was as a person, and Maitimo knows who Leareth is as a person, probably more confidently than Leareth knows it himself right now. He has teams out scouting for the right sorts of locations. The first one will contain instructions to all the other ones, and then they just have to intercept Leareth before he makes it north. And of course that probably just ends in another fireball, another search, but once they have the list of caches they can win that game as often as it's necessary to play it.
He could do it faster with more help from home - Quendi have better vision, better instincts, can communicate at greater range - but that'd strain the alliance between Sauron and Vkandis very badly, and it is already requiring all Maitimo's finesse to manage. Vkandis doesn't want Quendi here. Maitimo is himself a compromise. Vkandis doesn't want this war conducted across two worlds. Sauron feels that in that case he should've helped more with getting Vanyel killed. If he's dead, there's no one on the Arda side that can mount any kind of response. If he's not -
- then they're leaving a lot of critical pieces out of all their strategic conversations for the sake of appeasing Vkandis, which means he needs to be rerunning all of those, separately, accounting for the Silmarils, accounting for the combinations of both magic systems under various stages of investigation -- accounting, a couple decades down the line, for Arda's own mages -
- if it were up to Maitimo they'd send Sauron back now with some of Iftel's mages to kidnap or kill all the humans, to assault Vinyamar if Vanyel is indeed dead, but it is not up to Maitimo and so they just have to work on a tight deadline. Win before Arda can rederive how to strike back. And the plan for that, of course, is one which Vkandis would hate, so he also needs a false plan for that, one that's not so stupid Vkandis loses confidence in his allies but which doesn't require too many resources to pretend to proceed with, because he will need those resources to devote to the actual plan.
He has told the priests of Vkandis that they're studying the Void in order to track down where Leareth's resurrection mechanism is hidden, follow him there, kill him for good. It's a pretty good reason. They seemed to enthusiastically approve.