6,562 ft. roughly approximates to 2,000 m.
The F/A-18C uses meters as its unit for elevation
The route tool does not infer from terrain elevation data.
It isn't ideal in the case of UX, but all route presets are saved within your Saved Games path and Config folder. Presets are saved per terrain/map and is an idiomatic Lua table with fields omitted when left blank:
presets =
{
["4YA FARP LONDON"] =
{
[1] =
{
["alt"] = 2000,
["type"] = "Turning Point",
["ETA"] = 900,
["ETA_locked"] = true,
["y"] = 69738.40625,
["x"] = 189386.109375,
["name"] = "RIVER",
["action"] = "Turning Point",
["alt_type"] = "BARO",
["speed_locked"] = false,
}, -- end of [1]
[2] =
{
["alt"] = 2000,
["type"] = "Turning Point",
["ETA"] = 1075.9200317096,
["ETA_locked"] = true,
["y"] = 76952.6484375,
["x"] = 179263.359375,
["name"] = "IP",
["action"] = "Turning Point",
["alt_type"] = "BARO",
["speed_locked"] = false,
}, -- end of [2]
}, -- end of ["4YA FARP LONDON"]
} -- end of presets
You can share either the preset definitions (e.g. ["PRESET NAME"] or etc.) or the whole file, whichever is most convenient for you.