Ok thanks, did a quick search and there's a few folks on DCS who saw a little reduction in performance the last update so might just be part of that. Also make sure there's nothing running in the background thats taking resources away from windows. After that I'd try playing about with your settings, you might find you want to run on lower settings for the campaign as it can be demanding when there's a lot going on. I found a good guide here: https://www.openflightschool.de/mod/book/view.php?id=236
Do you use TACVIEW? if so I would disable it as it can be quite a performance hog in big complex missions. Should you use any winwing equipment they can be run scripts in DCS that affect performance, so disable them as well if this applies.
It is fairly high elevation, but it has always been possible in the past. I'll recheck myself soon, past Harrier updates could well have altered engine performance. No harm in a rolling VL landing though, tower will be perfectly happy with that.
TDOA can be enabled easy enough, but it wouldn't help as you don't normally operate as a large enough group of aircraft to make use of it. 2 aircraft isn't enough.
Thanks very much. Yeah you'll find all the missions a little longer than FIWOS due to the longer trek across the sea, but gives me a nice space to make things happen in so I quite like it.