Scott - Yes I did give saniflow a mention initially as this opened up the thread to alternative suggestions.
A local plumber had suggested this as an option and I wanted to run it past Questers as food for thought. With the ability of hindsight, and without doing a Gazza (edit Ed), I readily admit having viewed the price

what was I thinking! Totally unsuitable and wouldn't pass the ronseal test. At the very least 'Dick Turpin' had the decency to wear a mask!
I think Steve's Lidl pump in a dump chamber will give the quick drop required and if ever the worst happened in a cellar area, it would clear out residual water automatically.
I've tested Gazza's modus operandi and this equally works just as efficiently though you need to be hand close to the turn-on/offable switch. No contingency for emptying water from a cellar if it ever flooded.
Thanks for the advice clearly based on experience.
Best
Tickers