Why not seal the ends of the pipe, if you haven't done already? There must surely be some sort of end-stop plug for 3" pipe?
That said, I'd agree, a bit of pipe is not really the ideal. Some kind of cushioned support would be better. Maybe strips of thick, heavy duty vinyl/silicone/neoprene rubber sheet/mat glued (not sure which - vinyl repair glue, silicone adhesive?) together to create a sort of ramp, but there would likely be problems with it staying put. Otherwise, some sort of sleeve that could be filled with sand - I'm thinking of something like a gym mat/pad with the foam replaced by sand; of course it would need to be seal-able - otherwise, a heavy duty inflatable or one/couple of those pool cover weight bags if you could find one of suitable dimensions - again, not sure how durable they are.
I'm likewise looking for a better alternative to the vinyl bath mats (three) that I have under my steps. With the density and little suction cups underneath, they do at least stay put, but the patterned, pitted top surface makes them a magnet for settled crud and algae. I've now taken to sticking the vacuum hose round the back of the steps for a few hours every day or so, which seems to help the circulation, but it's a bit of a pain hooking up the hose/skimmer suction plate so frequently - ideal would be a second (minor) return behind or just to the side of the steps - maybe next year.
Incidentally, I did have a look again at the Innovaplas suction feet - they come as standard with the latest models. Granted the one I saw in a showroom here was in an empty pool, but I have to say that the suction feet did look a bit flimsy and in order to retrofit them to an earlier/different model of step there needs to be enough width on the step base flange to drill a 1/4" hole - I can imagine that over a period of time, with movement, the plug-neck of the suction cup might sever. So, great idea, but I don't think very durable.