Owning / Knowing CRISPR (or TALENS) gene editing techniques is not enough. You also need intimate knowledge of silkworm and spider genetics and silk production systems. Your first and third references have almost nothing to do with spider silk production by silkworms. Your second reference: https://phys.org/news/2018-08-gene-technique-silkworms-spider-silk.html message_id=137658270 however is Fascinating!
Mostly it is fascinating to see how poor the peer review process is for PNAS! It is amazing that these guys could get an article published in PNAS for supposedly original work without referencing another article published in PNAS (THE SAME JOURNAL!) a few years ago describing the successful accomplishment of the same goals which these researchers FAILED to accomplish. This recent article talks mostly about the methods (TALENS) and procedures used in an attempt to de-emphasize the fact that they Totally Failed to meet their goals. Some quotes from the article:
"The presence of the MaSp1 peptide significantly changed the mechanical characteristics of the silk fiber, especially the extensibility." "The transformed silk fiber showed lower strength but higher extensibility than that of wild-type silkworm silk fibers."
....posterior silk gland (PSG) (31), we further investigated PSG development in the PJET-DsRed-MaSp1 animals. PSGs of both heterozygous (MaSp1+/-) and homozygous (MaSp1+/) animals at the fourth day of the fifth instar larval stage showed a significant reduction in weight and length compared with the WT animals (Fig. 2 A–C). Paraffin-embedded sections and subsequent hematoxylin–eosin staining revealed that PSG in the WT animals was dense and filled with proteins. However, MaSp1+/- and MaSp1+/+ PSGs displayed atrophic secretion, accompanied by small cavities (Fig. 2D). This result indicated that the total protein amounts significantly decreased in MaSp1+/- and MaSp1+/+ PSGs, probably due to the low molecular weight of MaSp1 (67 kDa) compared with the high molecular weight of FibH (350 kDa).
BOTTOM LINE: 7 well funded postdoc candidates got to play with some nifty tools. They obviously knew about KBLBs transgenic silkworms and tried to duplicate them using the latest and greatest tools. (note: even if they succeeded they would not legally be able to compete with KBLB) They worked very hard and had a lot of fun and their final end product was a bunch of defective mutant silkworms that could barely produce any silk. They tested the small amounts of silk fibers produced and found that even though they were more than 1/3 spider silk, they were weaker than normal silkworm silk!