Nothing to do with staffing, and the determination of the RLSALT has nothing to do with CTA steps.
However, for routine application, they can only be applied within controlled airspace. And they are only mapped out to 40nm from the CTR aerodrome.
All the radar TCUs had their RLSALTs reviewed within the last 2 years - a very laborious and tedious manual process...
I couldn't use my pilot calculated LSALT anymore as they had vectored me away from the planned route.
In this scenario, I'd be requesting vectors to re-intercept your planned track.