So increase the proposed range then. If the effort to build up a system to a certain state is 10 times greater (by tonnage added up) than the effort to build a single outpost, then make the range from that system's contact 16ly x 10 = 160ly.
If the aim is specifically to discourage chaining minimal systems out because it's aesthetically displeasing to a subset of the player base, making chaining not the min-max option is certainly required.
The tricky thing here is that the benefit of range depends on what you're trying to do with it.
- if you're trying to chain in a particular direction, range is roughly linear in benefit. If it takes you ten times as long to build a system, you need ten times the range (though that still implies that a chain of single Colony Orbis stations should have 10x the range of outposts)
- if you're trying to bring more systems into range in general, range is roughly cubic in benefit. If it takes you ten times as long to build a system, you should get just over twice the range.
So if you make the benefits roughly linear to discourage chaining (or at least make them much sparser so you need third-party tools to spot them), a single developed system on the fringes of the existing bubble (or even somewhat within it) suddenly brings another bubble-sized volume into range all at once. But if you make the benefits cubic, it doesn't discourage chaining at all, which is the intent [1]
If it was just about "choice" then the people complaining about chains would have been mollified by the
vast majority of colonisers choosing not to build them already.
(Indeed the majority of colonisers, by Frontier's released numbers, don't even own a second system at all yet because it takes a while to secure their first and Frontier turned it off before they could even if they've wanted to)
[1] I don't actually get why a chain of undeveloped outposts between two more interesting places is seen as a problem anyway. Lots of real-life settlement patterns are like that (or were, when travel was slower) - coaching inns on the roads between major towns and cities. The Colonia Bridge - with sparser placement - does the same: most of its systems are a single megaship, with just a few (some pre-existing on the route) built up further.
If you're more into the whole architect aspect (which I'd argue is the meat and potatoes of this update), then why not get this increased range as a benefit / reward?
As someone who is into the system building side - I have one system with plenty of slots and have just finished its second construction - increased range is absolutely useless to me. By the time I've finished this one [2], if I did want to build another system further out from the bubble,
someone else will have put a colonisation contact or fifty further in that direction.
Same applies to all the 75%ish of systems whose colony/attempts are within the bounds of the previous bubble and clearly not trying to chain
to anywhere, and most of the rest are expanding its fringes as roughly ellipsoid clouds where again the way to get "further out" is to wait for someone else to colonise an intermediate system and build on from that. Actual identifiable "chains" are extremely rare already.
Personally, I think a short range is good for the geographic interest it brings to those who
do want to chain out to something distant - you actually have to plan your route a bit. 15 LY is a good compromise between "you couldn't colonise a good number of existing bubble systems" and "you can just go in a straight line", though an increase to 20 LY would have advantages and still be within the trade-off.
[2] At the current rate I don't expect to actually finish it. I certainly don't expect to build anything T3 in it.