You are welcome , anytime !
The problem of loosing the UI should be the least of the problem , and easy to fix ... Lets go to the basic of the driver , o.k ?
I was looking to yours picture , more closely . LEDA 1624 seems to be a simplified version of a N-chanell FET Switching Regulator Controller , that is getting the PWM from the U2 circuit (with a flashed modes , factory set ). This one should have a duty-cycle according with the UI modes.
The duty-cycle refers to the total amount of time a pulse is "ON" , over the duration of a cycle. Longer time on , bigger the current on load. Logic , is it ?
This is a simplified loop : Duty-cycle generator , Switching Regulator Controller, FET ,Load (LED). Inside this loop you have feed backs that are comparing the "in" and "out" , in order to have a balanced system. These are not what we are interested in , so let ignore them , for the moment...
So , LEDA is driving the FETs and provides the feed backs from sense resistor , in order to "hold" the current within the limit imposed by the duty-cycle.
When you mod a driver by decreasing the sense resistor , the biggest increase of the current thru led should be in the high and turbo mode , where the feed backs capabilities will NOT be exceeded ,BUT in the lower modes should be very close to the original modes.
Increased currents in lower modes means that the inductors are going in the saturation zone , that should be avoided (massive heat , loss of magnetic permeability...). Because of this , I was pleading for strong inductors , hand made...
Do not discourage , You are good , I'd seen this , just be patient , make a plan of what you have to do , and do not expect miracles.., every hundred of lumens counts , is better than before , we are the ones that knows better...!!!!
See you around , we are here for you , I'm sure that more guys will step in , with better solutions than mine.., you'll see ...
That's why , when you mod a driver , this has to be done in small steps (that is not hard to do when you stack resistors in parallel !) . If you loose the UI , it means that you lost the feed backs , and you have to increase the sense resistor to the value where the feed backs are capable to hold the system stable ...
So , do not worry about lost UI , could be fixed , within decent limits .., you can not ask to a driver designed for 100W to deliver 200 W !!! Unless you change the power side , accordingly with what you want .The small signal side as able to go up to 600W , or more...