Fighter jets for the Air Corps?

It's not quite that simple. Bas 90 calls for dispersed aircraft stands, short runways and other infrastructure built in the proximity of, and connected to the main base by taxiways masquerading as roads, as illustrated in the diagram below, which I've grabbed from Wikipedia

The completely independent highway strips you mentioned were developed as part of that program's predecessor, Bas 60, drawn up at a time when Sweden was also still pursuing a nuclear weapons program. It was also under that program that remote civilian airfields were built up as additional dispersal facilities. Those highway strips have been partially built back, and Sweden has closed a number of airbases. However, the infrastructure connected to the remaining operational airbases is still there and being maintained. You can see them on roads around bases such as Såtenäs, Jokkmokk or Hagshult, and they're still clearly visible on the likes of Google Map.

Austere bases with the bare minimum of infrastructure and support equipment are probably going to be all that the budget will allow if Ireland ever does move ahead with equipping a proper airbase.

Sarcasm aside, I guess my own perspective is partially warped by what I know from Germany. In former West Germany, every Landkreis, that is every county, has a general aviation airfield or stretch of highway is either already capable of accepting military airlifters and lighter aircraft or can be adapted for that with relative ease. That's in addition to any commercial airports or air bases that might be present, although some of the country's more mountainous counties obviously lose out in that regard. The origin of this obviously lies in the Cold War, but increasingly, these airfields and roads are becoming useful for civil defence purposes, given the increased prevalence of wildfires, which are also increasing in severity.

Having had much of the afternoon and evening to think things through, I've come around to the belief that it would be prudent for Ireland to have a few sections of road prepared in a similar manner, especially in areas with sparse infrastructure, not from a military point of view but from a civil defence standpoint. I'm aware that Ireland is significantly smaller than Germany, but there's little doubt that the frequency and intensity of destructive weather events will increase here as well. Should a large scale civil defence response become necessary as a consequence such an event, it is simply prudent to have such prepared areas of road available as forward staging points, rather than having assets such as helicopters or PC-12 Spectres flying top cover staging out of larger airfields in the rear.

I'm aware that this might come across as both fanciful and alarmist, but I'm a firm believer in having something and not needing it rather than the other way around. And given the fact that Ireland doesn't even have general aviation airfields in every county, as well as the fact that getting a road upgrade voted through is significantly easier than getting approval for a new public use airfield, upgrading sections of road is simply the most feasible way of improving Ireland's preparedness. However, Ireland's approach to civil defence seems to be even more apathetic than its approach to military matters from what I've seen, so I guess I shouldn't be holding my breath…