Thank you for the detailed response.
What you say on the tax relief makes sense. I've ramped up my contributions while the going is good. My future planning expects the top end relief to go at any moment, so anything gained until then is a bonus.
25% tax free - okay, fair enough, you'll be ex-UK. I'm not a big spender but retirement will coincide with my boy coming to that age where BOMAD may avoid a lifetime debt-servicing for him, hence my curiosity.
State pension agree, sadly national insurance contributions will be just that - insurance. On a similar line of thought who's to say the NHS won't by then be means tested - that in combination with unfortunate events or genes could well bring the state pension back into play.
Reaching LTA isn't a target but it would coincide with retirement age at a theoretical 4%/yr growth and employer contributions remaining high. I say theoretical as reaching the LTA feels more in hope than expectation in the short term as I expect fund values will sometime soon crash in a market correction; but I haven't yet acquired the skills or courage to switch funds to attempt to ride the storm! Anyway, back to point, at 41 now and reaching LTA feeling distant, ISAs aren't in my thoughts. To look at things more optimistically I could be ready for FIRE on paper in my early 50s if the pension funds perform well - so taking your point bridging the gap with ISAs and the like might come into my thoughts nearer the time - a nice problem to have!
Thanks again for your time, and the blog which I follow.