Speaking about increasing our source of income you know that doesn't happen over night. Even the Bitcoin we invest in the ROI doesn't happen immediately. We have to wait and usually this waiting period is always a long one. Assuming someone who wants to invest in Bitcoin chooses to increase their source of income it inevitably means they will still have to take from the money set aside for the investment to create a new source of income which we all know might not yield profit immediately as well. Infact the chances of the new source of income survive might be 50:50 especially if proper time to nurture the new income is lacking.
In real sense before anyone will think of investing in Bitcoin they should have other sources of income. Even if it's not sources a single source of income should be fine as well provided it will take their attention away from their Bitcoin investment until it matures. Digital assets can come with so much emotional drama and all and if there are no another means of earning money then temptation to sell will want to set in and this takes extra discipline to conquer.
Buddy it seems you're getting the whole thing about one increasing his or her source of as they are actively in Bitcoin investment wrong, I think this simply means investor making sure that they have more than one source of income to help them to either to keep increasing their DCA level and also scale through easily without having the thought of selling prematurely or discontinuing their investments in a short while.
Though I understand what you meant but that's not what one increasing his source of income means, you dont need to tamper the existing money that's meant for the said investment to set up other source of income because if you do that,, you may miss the whole process and you know what that means, rather we are talking about seeking for different upgraded source of income that will help you as an investor to invest more and hodl for a long-term with any form of change of mind halfway.