i think segwit established that BIP9 is an inferior activation method. miners should be able to accelerate activation but not block it. a BIP8-style flag day activation---done on a reasonably long time frame vs BIP148---seems appropriate.
i do hope we can avoid another recklessly hasty fork like BIP148.
Miner-signalling is only for that purpose, to signal that they're ready for an upgrade. It was never intended to be a political tool to exert control for themselves, and what they want for the network. BIP148 was merely a reaction from the community.
nevertheless, BIP148's timeline was dangerous and conducive to a network split. it may have been proposed on the mailing list a month or two prior, but the UASF campaign essentially began ~2 months before flag day. that was very little time to amass full node support and thus pressure miners to prevent a network split.
i'd like to see a 1+ year timeline for a UASF. miners can activate earlier if they want to, but that seems like a reasonable minimum given the risks.