Alright, lets ask this question again..
What are the constraints of budget reconciliation?
You've said you read it, so this should be an easy answer.
You must have a budget resolution, and it's limited to spending. Otherwise, you cannot pass legislation with it that is simply regulatory. As to what you can pass with budget reconciliation:
The Consolidated Omnibus Budget Reconciliation Act of 1985, better known as COBRA, which lets ex-employees stay on their previous employer's health plan.
The Omnibus Budget Reconciliation Act of 1990, which raised federal income tax rates, famously violating George H.W. Bush's "read my lips: no new taxes" pledge.
The Omnibus Budget Reconciliation Act of 1993, also known as the "Clinton budget," which included substantial increases for high-earners in income, Social Security, and Medicare taxes, and dramatically expanded the Earned Income Tax Credit.
The Personal Responsibility and Work Opportunity Act of 1996, aka "welfare reform," which dismantled cash welfare and replaced it with a block grant to states.
The Balanced Budget Act of 1997, which included substantial spending cuts and created the SCHIP program for children's health care. In conjunction with the 1990 and 1993 laws, it played a big role in the balanced budgets of the late '90s.
The Economic Growth and Tax Relief Reconciliation Act of 2001 and the Jobs and Growth Tax Relief Reconciliation Act of 2003, collectively known as the "Bush tax cuts."
The Health Care and Education Reconciliation Act of 2010, which nationalized the student loan industry and amended the just-passed Affordable Care Act by boosting subsidies.
The fact you are unwilling to blame the Republicans for not funding Trump's wall when they had 2 years to do so reveals the fact that you don't care about the wall either, you just want to try to shift blame to Democrats.