I’ve been giving this some thought, whilst listening to a live album of a band with only one guitar player and doing the ironing (a mindless task that allows me to think of other things). What is missing when the rhythm guitar drops out and the lead playing begins? Most times, it’s an upper midrange tone, with some drive. Therefore, having a tone with those components and perhaps playing more (8th notes instead of quarter, 16th instead of 8ths, etc), should fill that sonic space. Aim for a Geddy Lee, Chris Squire, etc tone and you shouldn’t be too far off the mark. If you’re already playing with some drive, just add some more at the appropriate juncture, whilst adding more upper midrange (it’ll sound awful soloed, but should work in a band situation).