The armouring of electrical supplies to brake cooling fans is a possibility ,but is a relatively minor mod. (esp in engineering terms).
The possibility of redesigned tyres was mooted but is not definitely ascribed to, and if it were to go ahead is some way down the line (years). The efforts to regain a CofA are not predicated on new tyres.
The only structural relevance of the liners is the fixing points - these are located to be of negligible significance. It is true that loads are higher on an SST in CRZ than a blunty, but the airframe is much stronger in this respect. Flexure on the Conc is greatest on take off and at it's least in the crz.