One way or another, Ageira is no longer the sole supplier of gate and lane parts and it would also be hurt incredibly badly by any kind of loss of sales in that department.
Is that not almost Ageira's entire business after all?
Liberty is not in a state to push its economic demands on Kusari/Bretonia/Rheinland.
So the assumption is that the lane/gate parts that Gallia produces is compatible with the lane/gate parts that Liberty produces? Have you looked at the lane/gate models that Gallia uses? They dont look similar at all, unless Rheinland just wants to replace their network and thus be in debt to Gallia to the same extent that it is in debt to Liberty. Hardly a better trade, given the size of their military (and before you say something about distance, I would bet that same distance would result in large logistical costs for the replacement of the lane network by Solar Engineering. Cant have your cake and eat it at the same time).
The only country that pushes its economic demands on anybody is North Korea (Kaesong Industrial Zone), and their people eat grass and dead leaves. And rice, on occassion.
Take a look at the economies of countries that are at risk of saying "suck it" to the rest of the world. You've got Greece and Spain, to name two, buckling under the pressure of their debt but unwilling to exchange investor confidence for a reset balance sheet. I wonder why?
People do not invest in countries that have a habit of not paying their debts. Therefore, countries that do not pay their debts struggle to find investors willing to buy their government bonds or privately support large or medium scale building projects. Just where does a government find the money to build a big bridge, pay it's wage bill or issue defense contracts, for example? Certainly not from it's own pockets. It would be a logistical nightmare to hold so much cash as a reserve, which is precisely why the vast majority of governments rely on the sale of bonds to deal with their cash-flow problems.
If a government does not pay their debts, people do not invest in that country. Why would this not be true in Sirius?
A bit like how you can't get a loan if your credit rating sucks. Which means you can't buy a car, house or other large investment unless you pay the full price upfront.
That kind of thing really sucks for countries. And well, Rheinland doing that would certainly give Liberty a very prudent economic reason for conquering the crap out of that house to make them pay their reparations rather than just stealing Munster. They got away with it once, but again? Political leaders don't like to be made bitches.
It's worth saying that if you want to justify the existence of these aesthetically tailored lanes, you could (instead of removing the vanilla basis of FL and a heavily influencing factor in the whole of Sirius' development before the SP storyline) simply say that the respective governments of each house issued slightly different specifications for the kinds of lanes and gates that they would like, and DSE built and maintains them to those standards. I'm not sure why they would do this, but that's why I think this is generally a bad idea.