I am not entirely sure what you’re asking for here. Those documents outline the borders of FRA, but AFAIK, those are not dedicated airspaces themselves? To quote your source:
The concerned FRA area consists of Finland FIR (excluding Helsinki TMA), København FIR, Norway FIR, Riga FIR, Sweden FIR and Tallinn FIR.
The highlighted FIRs are in Navigraph Charts, they’re just not highlighted separately for the FRA purpose. You can see the effects of them being under FRA by looking at the amount of airways in these areas.
Pilots plan lots of routes orderly via airways which have even upper FL limits also and while it while it wouldn’t be mandatory) which makes no sense at all and them fly lots of zikzak, as they don’t realize that they will be flying in free route airspace as designated in those charts.
If you look at for example southern half of Norway (screenshot below), there is a LOT of airways due mountains but still it’s free route airspace over FL135 which ain’t defined or highlightable in Charts. So it would be convinient for pilots to have chance to know if there is free route airspace available.
So I wish that all those free route airspaces would be defined in Charts as they are in real life, because not only it would make route planning in Scandinavia more realistic, it would be more usable in training purposes within flight sim community.