Thanks @liamc . The Syncing Axes ticks feature is welcome, no need to use workarounds for that anymore 
Do you know whether there will be some changes regarding the fine tuning of the legend item sizes in the near future? I’m thinking of the bubble charts; currently when the bubble area or diameter is not defined by a constant “marker_size”, (i.e if the area/diam is is dependant of a value) we can either chose to keep the marker size as constant (in such case it has a “default size” which is relatively small) or set it as variable. In the latter case, the legend item size might be too small.
Would the possibility of “scaling” the legend item size make sense?. This way proportions would be kept, but legends would be more readable.
Also, on scatter plot, if the marker_size is manually set to something larger, then the marker on the chart and in the legend get larger. It makes sense, but again, if we could “scale” the marker size in the legend, wouldn’t it help to fix the issues described there : Increase the size of legend symbol in plotly - #2 by empet or here: How to resize legend items - #10 by David22 or r - Change legend size in plotly chart - Stack Overflow ?