If in fact you are asking about keeping a remaining working engine running in gear to help a bit with a tow, sure, that could help reduce drag a lot at low rpm, and the tow line would help keep the bow headed the right direction. But if you apply too much power the tower will be PO'd your vessel is pulling his ( or hers) to one side instead of directly following his stern . Do NOT impede the tow boat operator's ability to maneuver both boats, including slowing/stopping!
However, you `need to know the major tow services have a policy of not providing tows of boat with any working propulsion system ( i.e. only 1 working main engine out of 2).
Depending on the boat, propulsion and operator, steering a T/I/B not under tow, with one engine down, can cause a LOT of stomach acid, especially in any traffic or narrow channels or adverse wind and current. If you haven't done it , you should practice it.
My 27'er T/I/B gasser with relatively small props and rudders will not steer straight at over ~7 kts on 1 engine even with the help of 1 trim tab fully deployed.