There are two issues. One is how to calculate the ceiling. The other is where you anchor the gf lo. The second is an implementation choice. The first isn't really if you are wanting to claim to be following Erik Baker.
I posed a simply yes or no question, which you seem to be studiously avoiding.
The only "issue" is whether to calculate your first stop the Baker way - i.e. the calculated ceiling is the first stop - or if you calculate it by factoring in the off-gassing that occurs during a 30ft/min ascent. GF Lo is anchored at the calculated first stop either way.
The example I gave is a dive using GF 30/70. At the start of your ascent, the depth of GF30 (i.e. your ceiling) is greater than 90', but less than or equal to 100'. So, your calculated ceiling is 100' and your Baker first stop is also 100' and your GF Lo anchor point is 100'.
The additional stipulation of the example is that during your ascent to 100' you would off-gas enough that by the time you get to 100', the depth of GF30 is now less than or equal to 90' (but greater than 80'). Perhaps it was only at 91' when you leave out off-gassing during the ascent (which gets rounded up to a stop at 100'), but it would change from 91' to 90' as you ascend. So, including ascent time in the calculation results in a first stop of 90', which becomes your GF Lo anchor point*.
The actual ascent, in this example, would be directly to 90', no matter which way you calculate the first stop/anchor point. The only difference is that with your (the Baker way) of calculating the first stop, you would spend less time at 90' before you ascend to your next stop, at 80'. With my way (factoring in ascent time in the calculation of the first stop), you would stay at the 90' stop longer.
Here are the GF gates for each depth:
Depth Your Mine
100 30 --
90 34 30
80 38 34
70 42 39
60 46 43
50 50 48
40 54 52
30 58 57
20 62 61
10 66 66
0 70 70
So, using either method, the diver would actually ascend directly to 90' before making their first stop. From there on, your diver would have a higher GF in his leading compartment at the end of each deco stop where he or she proceeds up to the next shallower stop. Your way gets the diver shallower, faster.
And, again, the simple yes or no question: Do you still think that the Baker way of calculating the first stop is more conservative, as you said earlier?
* Sure, if the dive specifics result in a difference in the first stop that is still in the same stop interval, then the two methods produce identical results. E.g. the Baker method calculates a first stop of 99' and my way calculates a first stop of 91'. In that case, both round up to a first stop and GF Lo anchor of 100' and from there the results are the same. The point is the difference when factoring in the ascent time causes the first stop depth to raise up into the next higher stop interval - e.g. from 100' to 90'. I assert that including the ascent time makes it the same or more conservative - not more aggressive.