Yes, a LIPO fireproof bag is also something I had in mind. I don’t know yet whether the batteries of the step can be removed. Maybe I should strap the step on top of the fuselage, space shuttle-style 
We just got Bromptons. Our nearest Brompton dealer is in St Annes, so we flew to Blackpool Airport (a very short walk to the nearest bus to St Annes), had lunch, bought bikes, rode back to Blackpool Airport. Two Bromptons fit in the back of an Auster just fine and they aren’t too heavy. We got the 6 speed versions and they ride really well and feel solid to ride (my normal ride is a normal Trek road bike, I’ve done around 6000km of cycle commuting on it in the last 12 months, and while I’m sure I’d be slower on the Brompton – I certainly wouldn’t pedal hard on the steep downhills like I do on my regular bike! – I’m pretty sure that doing my normal hilly commute with headwinds would be practical on the Brompton).
I love Bromptons and I even tested them on a trip with a Mooney. But they are really expensive (I need two) especially compared to those electric steps. I still need to pour a lot of cash into the resurrection of my plane therefore I need to make choices. Two Bromptons would equal a JPI 900, for example 
alioth wrote:
I’m pretty sure that doing my normal hilly commute with headwinds would be practical on the Brompton
I’ve done many many rides of a few dozens of Km (max I’ve done was about 100 in a single ride). They ride wonderfully (but I do tend to be a bit more confident with my road bike on steep downhills)
Brompton are exceptional :-))
And they can be nicely improved.
It is French but you ll have a preview of what I invested time in, some time ago :-)
https://www.bromptonforum.net/t8359-en-retour-et-remerciement-pour-tous-les-conseils-recus-mon-m6l
With some research, you can really find good parts to fit.
There is one more thing that can’t be seen is the second chainring. It is manually operated, but it allows you to climb trees :-)
The only plane I haven’t been able to take mine in was in these:
I take mine regularly on airliners (as cabin luggage) as it fits nicely in anything that is larger than a 318 or 737 – There are smaller regional liners (like a dash8) where they don’t fit, but usually you can gate check them and get them at the gate when existing the plane – avoiding them being “handled” too much.
I got two Gocyles. They are ok, usually I disconnect the batteries as it shoild be, when you carry something similar like this on passanger planes. I carried them up and down in Europe.
On my version it a a bit complicated, to disconnect, on the new version of Gocycle easier.
I have fireproof bag too.
The only problem experience, when the custom wanted to see the bills of the bikes in Cannes. The officer was really really rude to us, I tried to explain, the I am landed from domestic French route, not even from HUngary which is EU too.
the custom wanted to see the bills of the bikes in Cannes
Good point. I’ll upload a picture of the invoice to the cloud.
That’s completely outrageous, surely? However, this “intra-EU customs check” was reported from Italy also (LIPV, IIRC).
There was a thread about e-Scooters and their batteries in PuF just recently. I think the gist of it was, it’s not really safely possible to contain/control a battery that decides to burn. As a single pilot in an SEP, you either get burnt, the plane burns down, or you get unconscious by the smoke. If you make a box that’s so tight the gas can’t escape, you have a bomb.
That said, the real risk of such an event is very low. Of course, no airline on the planet allows these batteries on their planes, but that’s commercial ops, not single engine.
