I think, however, for the whole period between this episode and the Algeron treaty,Graham Kennedy wrote:No, they wired it in and turned it on. It worked fine, apparently - enough that the Romulans couldn't find them as they warped back to Federation space. No mention of it not working as well or only for a short time.
it is almost 50 years in which the federation could have adopted and developed a cloaking device and did not do so, at least on the flagships (Enterprise and Excelsior), although not having treaty impediments.
this is more difficult to explain, even more so if there did not seem to be major technical impediments to doing so.
The excuse "Our crews don’t go sneaking around in space.” doesn't make sense to me, nothing forces you to use it in peacetime, but it's an extra option in combat situations.