I have 2 issues. I have an existing 3/4" hardwood oak floor, installed in 2007, for which I want to install recessed floor vents for my HVAC.

1) I have an oscillating tool and using a couple different MasterForce blades, but often the wood is burning. 1 blade is for Wood and the other is for Wood, wood with nails, plastic and soft metal. I am not hitting any nails. However, I am burning thru the wood. Am I going to fast? Do I need to keep pulling out to allow sawdust to escape or get vacuumed? Is there a specific blade for oak hardwood flooring 3/4?

2) The vents are about 1/16" higher than my floor. These vents are not in any traffic paths, sometimes we may step on them as we look out the window. Is it worth trying to sand down the backside to reduce the 1/16 or is there a better way to deal with this?

Thank you in advance.

There are specific blades for hardwood. Bosch makes one. Make sure they will fit on your tool. Lots of blade manufacturers and the quality varies. Bosch reviews as one of the best.
If the vent stands 1/6" above the floor surface and you remove 1/16" from the underside of the vent what will support it? If the vents aren't fragile and won't be bothered by being stepped on occasionally then I would be inclined to leave them alone. Another option would be to route a 1/16" recess in the flooring to allow the top of the vent to sit flush with the surface of the floor. This would require a router to do.

Thanks for the tip on Bosch blades. I will have to review them.

As for item #2. I am referring to the entire height of the Frame and grill that sits flush tothe frame. The entirety of the two are not truly 3/4" to match the 3/4" of my floor. I am cutting out the floor for the entire vent to sit flush. Therefore the frame and vent sit about 1/16" higher. I may just leave it alone, its so unnoticable unless you look for it and feel for it if stepping on it.

My critical mind though would like it to be perfect, but messing with 1/16" may be short of the need for therapy LOL