I’ve not read the article yet but an owner of an internal tyre plug company recommending internal tyre repairs as safe screams of conflict of interest to me @T.C
It was a few years ago. But the point was, that the tyre manufacturers deemed an internal plug to be safe otherwise the instruction would have been to replace all punctured tyres.
Some companies such as Avon were happy for a tyre to be plugged twice, Michelin said once only and so there were variations.
The said chairman had to have integrity because his duty was to the national safety standard, and had there been deemed a conflict of interest he would not have been made chairman and the tyre companies would have boycotted any further meetings.
The recomendations about being no further than 50% from the centre of the tyre, side wall not comporomised and so on was introduced by the tyre companies themselves.