Aye Alex,
Sorry to read that you are not getting along with the 250.
I can only say that when swopping from the SRX/BROS to the Duke or the Morini, I have to re-programme the brain before setting off and make a concious mental note of the change. I too have on occasion locked the rear up looking for a lower gear!

Thankfully, I don't have the Embra traffic to deal with, afore getting out on the open road. The 450 doesn't like stop-start, traffic light interupted short runs. Personally, I wait until the daytime mayhem has abated and go for a canter in the evening, when others are gorging beer/wine and fast-"food"! I find it more relaxing!
If you are determined to make a conversion, I think that you will be on your own. But, corrspondence with Phil Hitchcock in sunny Oz, may illicit some measurements for a conversion (Please share them on here if you obtain anything. Thank you.). I believe that Phil sold up 'Road & Race' to go and "do other things"! Phil modified his race bike to a left-hand gear change and with a cable operated rear brake from the righthand side; the cable being looped under the swingarm pivot plates and away from the underslung exhaust. I have copied the link to the images on the 'ducatimeccanica.com' website below.
Phil_Hitchcock's_left-hand_gear_change_images_linkAs an aside, I suspect that you and others would enjoy a trawl through the 'ducatimeccanica.com' website, so here is a link to that.
'ducatimeccanica.com'_linkGood health, Bill (up the road), over 20°C for the first time in 2021!
