At Keystone you offer a high value and highly expert service. As a lawyer, you address every issue and allow the client to decide, fully informed by you, of all the pros and cons entailed with the decision.
If you work inside another business, you are typically making quick decisions, you don't have to look at every single option and you are typically not paid £000s per hour. Trying to be both a member of another business and its legal adviser can confuse the client as to what your services are worth and how you deliver them. Working in-house and in a proactive practice could not be more different. You risk making the client frustrated if you won't make quick decisions at Keystone, or, if you do, you risk being negligent. The client cannot waive or reduce your duties as a lawyer. Your advice needs to be perfect and to address every relevant point. Further, if the client sees you at one price for your in-house role, they will struggle to pay several times that for your private practice support that they may regard even as a lesser service.
Even where you decide to work in-house at one business and not to act for it in private practice, you need to be careful what other clients and potential clients hear about this. Will you be on the in-house website for example? There is a risk of doing more harm than good to your business plan by working in-house.
A specific point for litigators: fee recovery in-house is limited and sometimes not possible at all.