Does oxygen tube length affect lpm flow delivery?

Yes. Upto 50ft does not affect liter flow - check with home care company will have sticker trach is 12ft.
Yes. The physics of gas flow are that doubling the tubing length halves the gas flow. However, respiratory equipment is engineered to accommodate for differences in oxygen tubing length. Most home equipment can handle up to 100-200 feet of O2 tubing and maintain flow. But check with your medical equipment provider. .