/u/nullc was asked in "Gregory Maxwell – I do not support the BIP 148 UASF – very well written, tx Greg!" which alternative proposal he'd find superior and gave bip-uaversionbits-strong as an example pointing to this diff. The diff uses a sample timeline from Nov 2017 to April 2018 for activation.
bip-uaversionbits-strong states in the motivation section: "This specification provides an way for full nodes to coordinate syncronized activation based on a median past time using the BIP9 state machine."
I'd welcome some more insights how "coordinated syncronized activation between full nodes" is intended to work, as I can't see this from the sample code and it'd best be described in text and amended to the draft BIP anyway.
Edit: I now realize bip-uaversionbits-strong is the original introduction of UASF by shaolinfry in [bitcoin-dev] Moving towards user activated soft fork activation however shortly after the discussion moved to and focussed on BIP148 which is the more "aggressive" way of activating segwit by orphaning non-segwit supporting blocks after a trigger date. I'd be useful to find out more about a BIP9 driven approach as asked above.