Still got my SL2 50 and if it is calm with no breeze whatsoever, that thing only weighs just over 2kg and is a joy to use.
I won't use a Gardiner extreme telescopic pole for 4st work unless it's really light winds.
Much prefer a heavier, higher carbon telescopic/modular pole for high work 25mph+
Always check the wind speed for the days of higher work. Have only had the hairs on the back of my neck stand up five times and abandoned the work for another day. Have to be sensible about high work and strong winds, not always possible to work on expected day so always handy to plan other work just in case.
Where would I get a heavier pole like you suggest?
Normally I would say Reach-it but the exchange rate is lousy at the moment, it's not worth paying over the odds and it would take a couple weeks if you ordered it now. I use their highest carbon poles, same with extensions that slot in between the poles so I can reduce it as I'm coming down each level. They are really rigid poles but slightly heavier when fully extended. Use the hose outside the pole so can easily pull off sections to make it much lighter as I'm coming down the levels. I use their widest radial lite brush and adapted the gooseneck so it's wide enough to reach the glass properly on deep sills.
Also use Unger ultra high modulous but they are expensive as well but also very good and similar to reach-it poles as I swapped out Reach-it's top five clamps for Ungers as they click locked better and easier to open.
Downside to using a telescopic pole is that you're using a really heavy pole for the entire building all the way to the bottom. Telescopic mixed with modular makes more sense to work with.
Main reason I decided not to go with Gardiner Ultimate pole wasn't the weight issue but the diameter of the base sections, would give me finger cramps being so wide making it difficult to grasp the handle with a tight firm grip unlike Reach-it and Unger which have smaller diameter base handles making it easier to grasp more comfortably for prolonged periods.