Comments on the text by some of our friends (to be discussed next time we go into drafting mode)
In CERN-OHL-S:
2.1 This Licence governs the use, copying, modification, Conveying of Covered Source and Products, and the Making of Products. By exercising any right granted under this Licence, You irrevocably accept these terms and conditions.
Maybe another "and" before "Conveying" would make this easier to parse.
[3.3]d) license the modified Covered Source under the terms and conditions of this Licence (or, as set out in subsection 8.3, a later version, if permitted by the licence of the original Covered Source). Such modified Covered Source must be licensed as a whole, but excluding Available Components contained in it, which remain licensed under their own applicable licences.
Maybe revise the first clause to "Such modified Covered Source must be licensed as a whole under this Licence...."
7.1 Subject to the terms and conditions of this Licence, each Licensor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in subsections 7.2 and 8.4) patent license to Make, have Made, use, offer to sell, sell, import, and otherwise transfer the Covered Source and Products, where such licence applies only to those patent claims licensable by such Licensor that are necessarily infringed by exercising rights under the Covered Source as Conveyed by that Licensor.
Maybe "exercising rights to the Covered Source under this Licence" would be a bit clearer here