But OAP is making the very good point that while a bespoke FJ TCAS would be great, holding out for the moon and stars may well leave us with nothing at all.
Re. your earlier response to Lederhosen, while it may not be a strict legal requirement to avoid an airliners TCAS bubble, not doing so without a good reason is surely inconsiderate and unprofessional? Even if he felt, as you charitably allowed, the risk was non-existent the tornado pilot ought to have considered the consequences of passing so close.