do you mean cb (cue ball) not ob (object ball)?
so you are kicking the cue ball at a spot on the rail but you dont look at the rail as you stoke your cue and hit the cueball you are looking at the object ball wherever it is on the table and regardless of how many rail kick it is?
Correct
(see edit at end). Once I see the rebound angle there's little point in looking at the rail. I'm already in line in my stance and the CB will go where I stroke it. I find it much more beneficial as far as speed control, spin transfer, shortening and lengthening the angles. I'd say on 1 and 2 rail kicks I watch the OB 85% of the time. I find it better to focus on the contact point/ghost ball/whatever on the OB as you shoot the CB. Find the rebound angle while aiming/planning and trust it. It's situational and for tight little tricks or close little safeties, sure focus on the rail.
I understand this sounds wacko but it works very well for me. It requires a bit of faith and being good at visualizing rebound angles and what your intentions of the shot are before you actually get down to shoot it. Think of it like trying to comb your hair or shave in a mirror. If you just do it it works, but if you start trying to plan your movements left or right in a mirror it suddenly becomes more difficult.
For whatever reason once I see the angle I find almost zero value in focusing on the rail. It's as if the rail doesn't even exist. You have to have faith/trust that you saw the rebound angle and go with it. It gives a much more connected/immediate feel to the hit on the OB. It basically turns a kick into a direct shot if you stop thinking about rail contact while executing the shot. When I kick, it legitimately feels like I'm shooting directly at the OB with no rail in between. The rail only exists if you think it should exist.
Think of the fly on the wall shot... it just works without calculation once you know the spot to shoot at. On those shots you're not thinking of first rail contact. There's no twilight zone stuff going on, just trusting what you saw while aligning your stance. The rail is inanimate, have faith the rail will not move and it wont!

Angles are angles, tracks are tracks.
If nothing else it quickly tunes you into why you miss and allows you to adjust to table conditions quickly. People talk about the benefits of closing your eyes in practice, this is similar... if you're looking at the rail, it's much more difficult to fine tune where you're actually hitting the OB. After a short while the angles just connect and you're not having to count diamonds or do little measuring tricks to figure out how to hit an OB exactly.
Sorry for the book, I tried to keep it brief... would be much quicker and easier to explain verbally.
EDIT: on 3+ rail kicks I usually just use a system or visualize what the CB will do off each rail and hope the table conditions agree.