I've been a "I'll be the guinea pig" user of 1-month IPTV service providers for awhile now. Currently using FabIPTV, which has a nice list of channels and uses the Perfect Player apk that you can sideload where you don't have to use Kodi, hit it straight from the Fire TV menu. It's about $10 a month and has everything but adult channels, which I'm definitely fine with for live TV. Quality says 720p but eyeball test wise is a little scaled down, but good for the price. Large list of UK and US channels and the PP EPG is

, which I care about to replicate the live TV pay experience. Can pause as well.
I will always keep SmoothStreams TV, which is the gold standard for sports coverage. Can't recommend to you guys right now because they are going through upgrades and most channels are in SD while they bridge to all 720p HD and dedicated non-sports channels, which they override currently for sports. Been around forever and very good at users/stream management, where alot of competitor IPTV services oversell and buffering enters the picture, never an issue over there so I'll throw up the bat signal for them once they're done their upgrade work.
Will give the one you guys are outlining above a shot, always looking for a better option here.
Highly recommend this sub-reddit on the IPTV topic, tons of good info and the grid they maintain with stats on all IPTV providers and user commentary is absolutely fantastic:
https://www.reddit.com/r/IPTV/comments/560nyo/collaboration_list_of_iptv_providers_their/?st=izu0rxm1&sh=4361834c