When you can find out all the preferences of all the chief pilots you intend to send your CV to, you will have the answer to your question. However, as chief pilots are people and are likely to change their minds about what aeroplanes they like, you may find it something of a struggle to compile a fully up to date list of CPs favourite single-engined aircraft.
In other words, you have set yourself an impossible task! If you have the opportunity to do some varied flying, take it. It will add to your experience and make you a better all-round pilot. It will also be fun. Don't worry too much about the effect it will have on your CV, as long as you don't forget to maintain the IF skills which are the bread and butter of a commercial pilot's ability.
Scroggs