The Board shall have the power to amend or alter the provisions of this article by regulation prescribing a distance less than 500 yards between blinds whenever and wherever such action seems practicable and desirable. The Board may adopt other regulations concerning the use of such blinds as may appear advisable to meet changing conditions as to hunting migratory game birds. The regulations of the Board now applying to such hunting are hereby continued in force until amended or repealed by the Board; however, the Board shall not have the power to alter in any respect the privileges prescribed for owners and their lessees and permittees in §§ 29.1-344 and 29.1-347.