The part I referred to is in fact almost entirely solved, especially compared to the peak.
The https://en.wikipedia.org/wiki/Belarus%E2%80%93Poland_border_... is one of them more symbolic part, though that is only one piece of puzzle.
It was built by Poland in very non-EU fashion (see below, "shall not apply to the investment. In particular, the following are not required"), but EU at least has not sabotaged it and in fact silently ignored some topics.
https://www.sejm.gov.pl/Sejm9.nsf/PrzebiegProc.xsp?nr=1657 Art. 6. 1. - English translation below:
> Separate regulations—including the Construction Law, the Water Law, environmental protection laws, regulations on the disclosure of environmental information, the Geodesy and Cartography Law, regulations on spatial planning and land development, regulations on the protection of agricultural and forest land, railway transport regulations, and regulations concerning special procedures for the preparation and implementation of public road investments—shall not apply to the investment. In particular, the following are not required:
>1) a building permit or a formal notification;
>2) a decision determining the location of an investment of public purpose;
>3) the preparation of a construction design;
>4) the obtaining of any other decisions, permits, opinions, or clearances, or the submission of any notifications.