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UK CAA definition of VLOS
Visual Line of Sight (VLOS)
"Operating within Visual Line of Sight means that the Remote Pilot is able to maintain direct, unaided (other than corrective lenses) visual contact with the UA which is sufficient to monitor its flight path in relation to other aircraft, persons, vessels, vehicles and structures for the purpose of avoiding collisions. Within the UK, VLOS operations are normally accepted out to a maximum distance of 500 m horizontally and 400 ft vertically from the Remote Pilot. Operations at a greater distance from the Remote Pilot may be permitted if an acceptable safety case is submitted. For example, if the aircraft is large it may be justifiable that its flight path can be monitored visually at a greater distance than 500 m. Conversely, for some small aircraft, operations out to a distance of 500m may mean it is not possible to assure or maintain adequate visual contact."
Based on this, Line of sight means "as long as you see it". So, Op, FPV or not, if you can't see it beyond 30 meters, this is the limit of your LOS and you should not operate further without a spotter.