Nope, as Merlin is in close cooperation with Asus and his firmware is accepted (he delivers an Asus approved version).I have just bought Asus 86U router. My questions are:
1. If I upgrade with Merlin firmware, will my warrenty be void?
Read here, install and enjoy!2. Key benefit to use Merlin firmware as opposed to the latest Asus one?
Q: Will flashing this void my warranty?
A: This is a kinda grey area for which I have no definitive answer unfortunately. I have seen Asus publicly commit to supporting DD-WRT for some of their models, without any mention about it voiding your warranty. Therefore my personal opinion would be that "No, it won't void your warranty", but as the saying goes, IANAL. Your retailer might certainly have a different view on this than Asus would, too.
NOTE: CSR Sanita, after confirming w/ her supervisor, said on 2/24/2016 "We will repair the product free of cost under warranty if it does not have any physical damage. No, it won't void your warranty."
The FAQ content is old (2016). In the meantime Asus has further locked down the firmware updates (e.g. no easy downgrades) and only supports "approved/signed" firmware versions - and guess what: Merlin's version is approved.
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