I've had a look at that part of the video and she is talking to health professionals here so sounds pretty casual about adding in extra oestrogen. Health professionals would know to be especially vigilant about adding oestrogen to these preparations which is very much off-licence. I would imagine if she were talking to the general public she would talk about this in a slightly different and I expect more cautious way.
As always the extent to which the progestogen is sufficient to protect the endometrium is dependent on the type and dose of oestrogen, the type and dose of progestogen and crucially the individual woman - absorption, condition and health of womb lining, presence of fibroids polyps, endometriosis etc so it is not univerasally OK just to top up without medical supervision.
In the case of Evorel conti - it may well be, because the same patches are used for the whole month in Evorel conti, and for half the month in Evorel sequi - ie the same dose of progestogen - so for some women adding extra oestrogen to a continuous combined regime of Evorel conti may well be fine.
Similarly with Femoston sequi - the dose of dydrogesterone for 1/10 is the same as for 2/10 (10 mg) so it sounds perfectly reasonable to add extra oestrogen to the cyclical preparation although another oral tablet would be better eg 1 mg extra every other day as otherwise it is difficult to gauge the dose. Under medical supervision and with regular scans it sounds like a real possibility.
Adding extra oestrogen tablet to Femoston conti is a different matter altogether because it is very much unlicensed so no-one should be just doing this withoiut discussing with their doctor. Once you are settled onto a continuous combined regime eg over a year (just made that up!) with no bleeding and ideally have had a scan then you know how your womb lining behaves and if it has remained thin then may well be OK to add in more oestrogen. Potentially though the lining is going to thicken so definitely with medical supervision.
Don't want to be a killjoy this Sunday morning but just always be careful
Hurdity x