Patrick, please do not give up any benefit income to which you are entitled to.
There is absolutely no problem or objection at all in you claiming and receiving any public funds to which you are entitled to in your own right.
It will not have any impact on the visa application.
Personally I would not advise you make any special issue of this as some ECO's may make mistakes about it, even when it is pointed out clearly to them.
But please don't give up your DLA.