After a lot of experimentation & running the sweep (with 2 remotes) Am now running - on remote & boost cable - 12 program cycles with the settings -

Out 1 Square Wave - Out 2 Inverse & Sync. F2 + F1 X 11 | Hz 0. Modulate F2 using F1 (AM DSB). Amplitude 20. Amplitude & Frequency wobble - Triangle - 1% - 16 Steps. All other settings are default.

Does appear to be helping a bit.