Or will it just feel tat?

what frame/fork? some seem to do fine with longer forks and others not so.
Also bear in mind if the fork locks out, it will probably do so at 130mm and give you a superb/daft chopper feeling on really steep road climbs.
Also rockshox air forks are mostly travel reduce-able by putting a spacer inside the air spring.

Pace RC41 fork – Salsa Moto frame

Are you talking about the Salsa Moto Rapido frame? If you are that was designed ideally for an 80mm fork and XC racing. If you fitted a 130mm travel fork it would put the head angle at about 66-67 degrees and significantly raise the BB height.

Whether that’s a good or a bad thing is down to you and how you like your bikes to handle. My personal opinion though would be if you are going to ride down lots of really steep and rocky terrain on it then it might be OK, if you are just going to use it for ‘general’ riding around though it’ll be pants.

I’d say you’d be ok IF there is brace/small gussets around the headtube/downtube. If you said a Salsa and Mazzorchi etc then definately not.

I used to run a 2001 RockyMountain Vertex with a old Psylo pair of forks so 80-100 and c120?

not something i would reccomend myself as it will ride like a dogs dinner.
allthough check the geom as this would help or hinder but on the whole it won,t feel right.

even with more sag the climbs will be hardwork & the downhills even worse.

lots of sag will tend to make the fork feel wallowy.

Better solution would just be to reduce the fork travel with a spacer inside if it’s not designed to be adjusted. You just use the spacer to limit how far the fork can extend. Simples

With loads of sag the fork will dive heavily under braking, on steep stuff, in corners and generally feel quite sloppy and uncontrolled

A fork too tall for a frame will make the BB hieght higher making it worse in corners, harder to get on/off and get started on tricky climbs/traverses/DHs
The effective top tube length will shorten
The chain stay length will probably increase on a XC hardtail (depends as to the angle)
The headangle will obviously increase, but will still dive to the same point
Most importantly though, the seat angle will be a lot slacker making it more difficult to ride in pretty much every situation but downhill
The increased travel has the potential to rip the headtube off too

Given its an 80mm frame I’d try to stick to a 80, 85, 100 (maybe a 105) fork, not just because they’ll likely be lighter, but much more suited to the frame

I’ve had 125mm forks on my 80mm corrected Lava Dome for 9 years now and it feels fine – the only downside being a slightly light front end on climbs. The head angle is no slacker than on my Enduro.