New Pico-8 exporter (works with meshes bound in [(-1;-1;-1),(1;1;1)] )

import.lua

function parse_vert(str, i)
	local s = sub(str, (i-1)*5+1, (i-1)*5+5)
	local v = sub(s, 1, 1)
	local res = v.."0x0."..sub(s,2)
	return tonum(res)
end

function load_verts(str)
	local verts = {}
	for v=0,#str/15-1 do
		local x, y, z = parse_vert(str, v*3+1), parse_vert(str, v*3+2), parse_vert(str, v*3+3)
		add(verts, {x, y, z})
	end
	return verts
end

function load_edges(str)
	local edges = {}
	for v=0,#str/6-1 do
		add(edges, {tonum(sub(str,v*6+1,v*6+3)), tonum(sub(str,v*6+4,v*6+6))})
	end
	return edges
end

pico8-export-v2.py

import bpy

def hex_repr(v):
    vf = int(v*65535)
    if not (vf >= -0xFFFF and vf <=  0xFFFF):
        raise AssertionError(f"{v} doesn't fall in the range")
    if vf < 0:
        vf = -vf
        return f"-{vf:04x}"
    return f" {vf:04x}"

def do_magic():
    current_object = bpy.context.view_layer.objects.active
    if current_object.type != "MESH":
        print("Make sure that the selected object is a mesh")
        return
    mesh = current_object.data    
    result = ""
    print(f"{len(mesh.vertices)} vertices")
    for vertex in mesh.vertices:
        x, y, z = vertex.co
        line = "{}{}{}".format(hex_repr(x), hex_repr(y), hex_repr(z))
        result += line + ""
    with open("c:/tmp/out.vert", "w") as f:
        f.write(result)

    result = ""
    print(f"{len(mesh.edges)} edges")
    for edge in mesh.edges:
        a, b = edge.vertices
        a += 1
        b += 1
        result += f"{a:03d}{b:03d}"
    with open("c:/tmp/out.edge", "w") as f:
        f.write(result)
        
do_magic()