at 100bpt it took 100 turns assume it used the new bonuses to reduce the cost by 40%

having considered it
the problem was not the conversion itself
its problem was that the conversion was too late
it got no regeneration
the timing of conversions has been debated on this forum several times over the past few months with no result
this conversion was way too late by at least six hours

and as for investing hundreds of millions of dollars in bus and res tech for an F farmer i see from your thread you did not make that mistake this set