You should be fine with any of the options because none of them stops you from doing what you want to do. Your employer paying you in Bitcoin or cash can still be used wisely when you want to do that. When you receive cash, you can distribute the money according to your expenses and keep the ones that'll be use for investing which you are then invest into Bitcoin. Having them splited into two which is Bitcoin and cash, can be of help to you because it saves you the time but when you're not disciplined and do really wants to invest in Bitcoin, you won't be able to save. We shouldn't wait until our salary are paid in Bitcoin before we start investing in Bitcoin. For me I'll accept any of the options and then decide how I want to spend my salary myself.