Most conservative accent

This topic came up on a thread a few weeks ago and I've been thinking a little bit about it since then. I'm speaking of course of linguistic conservativism; nothing to do with politics. I think some of the acrolectal Carribean varieties are probably the most conservative in terms of phonology. A few conservative features:
1. Full or partial rhoticism
2. No low-back mergers
3. Monophthongs for FACE and GOAT
4. [a] for TRAP (never raised)
5. Back onset for MOUTH [mVUT]
6. Preservation of phonemic length
The only innovations I can think of from Early Modern English are the cheer-chair merger and the fir-fur-fern merger. The suprasegmental features are very different too, with many Carribean varieties being stress-timed and/or pitch-accented.
Anything I missed? Any other accents that are more conservative?

The very notion of conservative, whether linguistic conservativism or not, sounds very filmy and fuzzy to me! I doubt the usefulness of the saying.

>>The only innovations I can think of from Early Modern English are the cheer-chair merger and the fir-fur-fern merger.<<

The main thing about the fir-fur-fern merger is that I doubt that the fir-furn-fern distinction ever actually survived in *any* English dialect proper, and it seems that its presence in Scottish English is due to its reintroduction from Scots due to substratum influence of Scots upon the English which replaced it much of Scotland. The reason for this is that this distinction is solely present in Scottish English, and yet Scottish English did not exist at the time the merger occurred as the language of Lowland Scotland at the time was Scots, Scottish English only coming into existance after the union of England and Scotland. Consequently, there could have been no direct continuity within English of this distinction in Scotland as English was not spoken in Scotland at the time and only spread to Scotland from England, where the merger had already occurred, a good while later. Thus, the only way this distinction could have come to be present in Scottish English is if it were introduced back into it from Scots, which maintains this distinction to date.

I've read that some Irish accents maintain it as well, but they could have been exposed to Ulster Scots and borrowed it from there, I suppose.

<<The only innovations I can think of from Early Modern English are the cheer-chair merger and the fir-fur-fern merger.>>

Other innovations from Early Modern English are the meet-meat merger, pane-pain merger, and toe-tow merger which haven't occurred in certain English English dialects. Of course, these dialects also have innovations which aren't presence in the acrolectal Carribbean varieties.

I'd forgotten about those. There's a couple other things I thought of too: no horse-hoarse merger, but also the trap-bath and possibly lot-cloth splits. Still, I can't think of any other accent that is more conservative.