PV Terminal Value/EV = 40% is too low?

Disclaimer: Valuation Post, if you are on Christmas/Holiday mood, I do not want to give you undesired work vibes. Therefore, stop reading here.

Context: I am modelling this company with belongs to an industry with tremendous growth potential. Until now, my COGS was growing with the production rate growth only. After redoing the financial statements analysis, I noticed that their COGS/Revenue Ratio never went below 50% (Price has cycles) So I added a new lower bound constraint that the ratio in the growth phase (first 5y) could not go below 50%, otherwise it will correct itself an adjust. Moreover, in the horizon (year 10), the constraint increases to 71.5% (taken from industry reports) to assume the company has mature. Years 6 to 9 are adjustment years with the rate growing with a linear interpolation between 50% and 71.5%. My PV TV/EV went from over 80% to 40%. I know that having a value over 80% is a red flag, but isn’t 40% too low? (Naturally the share price went from 35 to 20)