Logically, yes, it must be based on mass if the problem is space-time shape related - too sheer a gradient or something?
However, as noted, if you can come up with a good factor of safety value then that's a pretty good shorthand. If it's good enough for a rock/iron world then it's probably good enough for anything they're likely to deal with.
Equally, if the gravity field is the problem, then logically, the same tech which produces an M-Drive's acceleration should be able to produce an 'interdictor field' - although pulling someone out of jump is less likely, it shouldn't be beyond the wit of man to prevent someone jumping. After all, a 6G acceleration represents a (localised) gravity well equivalent to a planet six times the mass of the earth....
However, as noted, if you can come up with a good factor of safety value then that's a pretty good shorthand. If it's good enough for a rock/iron world then it's probably good enough for anything they're likely to deal with.
Equally, if the gravity field is the problem, then logically, the same tech which produces an M-Drive's acceleration should be able to produce an 'interdictor field' - although pulling someone out of jump is less likely, it shouldn't be beyond the wit of man to prevent someone jumping. After all, a 6G acceleration represents a (localised) gravity well equivalent to a planet six times the mass of the earth....